Can we also have solar panels that are smaller than the current one like the ones on a Soyuz. I'd also appreciate more station parts like science modules. One more big thing. What about other systems with the ion engine you're considering?

What about an ion drive? It is solar powered and we already have solar panels.

So basically high power low efficency engines and low power high efficiency engines? Doesn't seem too hard

BIgger Parts - although you would have to make textures, they're possible through modding.
SRBs - not really necessary...
Types - not necessary, modding in different sized tanks or different engines with different fuel consumptions and power outputs would be an easy solution to this.

Its always moddable.

Funny thing though is that the larger blasto looks exactly like a NERVA.