As mentioned recently, I prefer the look of 4 tips over 2 oval ones on 4.6is. The trick is to pick the good quality and avoid cheesy look of some E Bay tips.
Some preliminary measures shows promising results with these while retaining classy look and quality. Even though they're probably made in China, they're double walled SS T304, nicely polished and just about everything made by this company is high quality with good reviews:
http://www.summitracing.com/parts/vpe-1209
The best price for 2 new stock tips is about $160-170 shipped and I'll let mine go for $110 shipped.
I have one interested party for my stock tips but I'll let you guys know if it doesn't go through.