ET35 will be sticking out from the guards in most cases for a k11. ET45 is standard and you might have trouble fitting a 7" wide rim with that offset. ET38 to 42 looks great on k11s and is a quite popular offset in japan with the Mazda MX5/Miata and Eunos Roadster so there's plenty of 4x100 rims in the right stud pattern floating around.
BTW Rota rims are cheap and nasty, I would avoid them if possible...
The real jap march use genuine brands like enkei, rays, 5Zigen (black racing), Watanabe, etc.
Rota is in the same class a Konig. A brand which wants to be percieved as high quality but really just specialises in imitation gear.