i believe the instructions are in both english and japanese..(someone corret me if i'm wrong.. i don't read the instructions much
)
as for easy to built.. the fujimi ones are pretty simple and straight forward, as the Tamiya one (if there is one.. sorry I didn't keep track of the Evo 7) they're more detailed and a bit more complicated then the fujimi kits (but it's no rocket science.. everyone can do it)
as for which one i like most.. personally, I don't like the Evo7, but i have to admit that the Moster Tuned Evo7 by Fujimi does look pretty neet
as for coloring.. most people prime the body before painting, so color of the plastic does not affect anything
happy building