I agree, the minimum should be 18". I have a set of 18" Enkei RSVs on my Gen2. I think the black looks awesome on a silver car. Chrome is not my thing but looks good on some cars.
Regarding size, here are my thoughts:
Determine what is more important:
- Ride quality (in areas with poor road conditions)
- Appearance
- Cost
I live in Michigan where pot holes swollow Yugos, Escorts and VW Bugs. One careless hit and my new wheel can be toast. Not to mention numerous expansion joints driving me crazy on the interstate. So I wanted a larger rim but still keep some rubber cushion between the wheenl and asphalt. For me, going with the 18" was the right choice.
Appearance is important as well. Since my car is lowered, I wanted to avoid that terrible "Toyota Gap" between the tire and wheel well. Since the OE tire fit in there so well, I needed to stay with a tire around 26.5" in diameter. For an 18" wheel, this pushed me to use 235/45/18 tires. (See below)
These tire sizes are the idea diameter to keep your speedo readings accurate and not increase the gap between tire and fender. Before you commit to the wheel change, check the tire prices. The 235/45/18 tires that I have were a rare size. I found these on EBay for less than $400 for a set. They are GoodYear private brand called Essenza. (A summer tire only) Otherwise, I was looking at $250 / tire for Pirellis.
Beware of the "tire and wheel" packages you get online. Mose sport compacts run a smaller tire so the packages are usually like 225/40/18. This is passable but I didn't like the increased gap. (Tire is around 1" smaller in diameter so the gap is + 1/2")
Hope this helps.