Really just depends on the rim honestly. I don't think big 20inch chrome wheels should be on a gp/gtp. However if it's a racing type wheel from a mfg that surves purpose for handling and performance it's different. Then again if you're getting 19's and they're not forged they're going to be heavy. You get what you pay for, forged 19's will cost some coin.
I had 17's on my type sh and I went back to 16's with 225/50/16 nitto neo gen tires. I could tell a huge difference! Just all depends what your goals are really. Not everyone likes the same thing, it was just my opinion.