I'm not sure a replacement would be welcome in this community, but people are always interested in complete ideas for new reactor builds using the existing blocks. (E.g. Special power bonus if you create a reactor with three non-touching enclosed reactor block cages with capacitors filling the spaces in the cage.)
A suggestion that I haven't heard yet: using power blocks on rails to create a mechanical reactor which the game interprets as a bonus. Examples:
Having a reactor block on a rail sliding between two power block lines to create some kind of (insert technobabble here) power bonus, like one of those flashlights you shake up and down to generate power for.
Having two power blocks on a rotor orbiting around a third power block to create some kind of rotary power bonus, like a conventional electromagnetic generator motor.