Yes, get the drop, the rims, and then the kit. If you don't, it will look funny like my car right now (but the rims are coming by this week).

225/40R18's should have no problem on a 6th gen. If you rub any, it takes a file and a short couple mins in the back near the rear bumper. That's the only place I hear that might rub consistently.

If you are going really low, then you might want the rims first so when you lower, you can choose the springs that are right for you. My friend dropped his prelude and after he bought rims, finding out that the rims touch the fender when it's not on a lift. Usually this isn't the problem on an Accord unless you're thinking about a drop more than 3"...and even then just this weekend i saw another member that has 19's with a 3.5" drop. (and it looked goooood)...