You'll look like a 4x4 or something close to that if you don't lower and go with any of those sizes as the stance is too wide.
I just got 18x8, +40s on my stock TSX and I look a bit raised now, a 1/2 inch drop would makes it look stock again though. I'm going to either go a-spec or go with H&R OE Sport Springs (it's a daily driver with a steep driveway to negotiate) to get the look right.
I wouldn't lower it too much because I live in Canada so winters can be crazy. If i were to drop it I would only do springs or something. Not really wanting to do any work really...don't know how to really do any of that stuff.
With a 8.5 width and a +20 or +30 offset, you will need work for BOTH if you're lowered. With a +20, you will have to cut fender liners, roll your fenders and pull them as well. With a +30 offset, you will have to cut fender liners, roll your fenders and possibly a slight pull. Of course, this depends on how low you are and how much camber you want to run.
If you don't lower it at all, you probably won't have to do any work on the fenders (with +30 offset). BUT, it will look REALLY funny IMO. If you want to get wheels that width with those offsets, it looks best lowered. If you don't lower it, it will look like a 4x4 and have a lot of poke. Just my 2 cents.