Stats depend ENTIRELY on what you want the ship to do. However, I can offer some advice.
1) If you're fighting ships of a similar size and those ships use missiles,
4 layers of advanced armor will almost entirely nullify their missiles due to the explosion dampening powers of armor. It will also make you completely immune to beams (beams can't get through armor without certain tricks that don't work unless you're using a much larger ship, and then they're still worse than cannons.) and will severely weaken the effectiveness of many machineguns.
Combine this armor with passive pierce and passive punch effects, which will greatly boost the effectiveness of this armor. These are absolutely necessary if you decide to use armor. This will make you heavy, but it will also make you very hard to kill.
I generally recommend "slow, heavy, and hard to kill" over "fast and hard to hit" due to how quickly fast but flimsy ships fall apart when hit, and it's generally difficult to avoid fire anyway.
2) Shield capacity and regen will vary depending on whether you want to be tankier or have more weapons. Generally, I fill in shields last unless the ship is a shield tank.
Ion passive is absolutely necessary unless your ship uses armor and thrust as its primary defense and has very few shields.
3) Missiles can make good support weapons, but should not be relied upon as your primary ship weapon since they can be shot down and can be countered easier by armor than cannons.
Missile/Beam with pierce, punch, and explosive are all good choices. Explosive will work best against softly armored targets, and the other two will work best against heavier armor. Pierce on missiles does NOT have a debuff against shields like cannons and beams do.
Missile/Beam works great on turrets since AI can lock onto and fire on jammed ships, can see and fire on enemies from up to 4 sectors away if you have 100% beam slave, and you won't need to stop firing your other guns for ~5s while the missiles lock on.
Make sure to include decoy missiles (broadside launched missile/cannon works great for this) to distract enemy PD while your lock ons are enroute to the enemy.
4)
Other weapons are a must. Men cannot fight with missiles alone.
Cannon, cannon/cannon, and cannon/beam (all with punch) are great block destruction options. Cannon/beam/explosive may also work decently. If you are going to use cannon/beam, I definitely recommend having multiple shots on separate computers each, so you don't need to wait 4 seconds between every shot. Cannon/cannon may have difficulty breaking through armor at small sizes. I would suggest shooting for 8k to 12k modules per output for a small ship. Adding more outputs will make you more effective against systems, but you may have more trouble with armor.
You'll also want a shield breaker weapon. Shield drain beams give you back what you deal to the opponent, but they're only half as effective as a weapon with ion, and they are seriously lacking in the range department. Other
good choices are cannon/cannon/ion, beam/cannon/ion, beam/beam/ion, and beam/pulse/ion. Rapidfire ion weapons are generally not something I recommend for smaller ships due to the large amount of size you need to dedicate to breaking people's shields with DPS. For smaller ships, I definitely recommend the alpha option, as it will allow you to zap enemy shields quickly at the start of the fight and start breaking their armor and systems up, and your can make your block destruction weapons larger since you're spending less block space on ion weapons.
Do not use missiles against shields unless you plan on fighting the enemy at extreme ranges only. Due to the pseudo-raycast damage system used by missiles, they are generally ineffective as shield busters because their damage can vary greatly.
5)
Expected features of a ship that size is a chain drive (
Jaaskinal's is the one I recommend due to its great control system), which will allow for easy, constant jumping in a very small package. You should probably have at least some sort of interior. Chances are decent that you may need a docked reactor for a ship of this size. It's right around the border of "rarely needed" to "essentially required." I've built ships around this size that have and have not needed them. It all depends on the power costs of your weapons, shields, thrust, and passives.
6) For a ship this size, I would recommend
2 to 6 turrets with 500 to two thousand weapon modules each. You'll probably want to equip these with cannon/beam or missile/beam to get the most bang for your buck out of something this size. Make sure to put a second missile system on your missile/beam turrets (missile/cannon or missile/beam, generally) to fire off distraction missiles so the main missiles don't get shot down.
POINT DEFENSE IS ABSOLUTELY NECESSARY. I recommend at least 4-6 turrets on each side of a ship, with 2-3 covering the top half and 2-3 covering the bottom half. One on your rear and 2 to 4 on your front end is also highly recommended. Point defense will save your life against missiles, and is probably the only thing that will keep you alive if you're running from a ship that's much bigger than yours. My personal PD design is this.
Each of the 4 side barrels are outputs for a cannon/missile shotgun system, which floods the area with cannon projectiles, and the center barrel is a cannon/cannon.
Cannon/cannon supported by cannon/missile appears to be the best entity-efficient way of dealing with large numbers of missiles according to both tests and combat, and I highly recommend a design like mine. PM me if you want a copy of it.
Best of luck with your ship, and remember, forums and chat will almost always have good advice if you need further help.