It's hard enough to even get builders involved in small building contests. These build requests never seem to end well.
A dropship large enough to carry a tank that has roughly the same dimensions as an Isanth IV is no longer a "small ship". It's not a titan by any means, but it will be big enough to allow for easy detail. Based on the look of the dropship in the picture, I would say it is easily 100 meters, stem to stern, 120 m from wingtip to wingtip (feel free to trim those wings shorter), and probably 40 m tall.
Unless the ship is designed to carry the tank sideways, which would be a weird, yet fun change. I imagine that if a 10-m tall tank were carried sideways, the dimensions could be cut in half, so 20x50x50.
The thing is, you'll just have to reconsider the design of the ship to improve efficiency. For instance, you may want to consider stretching the top wings forward to attach them directly to what I am assuming is the mid-ship engine pods. Then you can have a flat panel of system blocks stretching through the wing all the way through the top of the engine pod. (Or you can leave them separated. That's OK too.)
For combat-dropships, I always recommend having side-ways disembarkation processes. You merely have to watch the beginning of "Saving Private Ryan" to see why frontal disembarkation designs are a bad idea for combat drops. That puts the disembarking troops directly below your engine pods, maybe, so they may get fried if there is a hot-drop, but them's the breaks. War is hell. Friendly fire, doubly-so.
