I'm planning on getting my tenzo type m rims in a few months or so, but do you guys think I would have a problem with 18" rims?

Plans are you get 18"rims and drop the car about 1" - 1.5".
:dunno:

18's are stock on some of the 8th gens and Honda sells 19's. 20's will fit fine, so you will be fine as long as you get the right offset ~+40