Bridgestone Potenza RE950 come in 225/45/17 (WR speed rated, but has a 400 tread wear rating), which you can use on your rim; its a "plus zero." (225/45/17 is very close to the overall diameter of 215/50/17 so your speedo wonn't be messed up any if at all). Many people aren't fond of the XGT H4, and they are expensive tires in my opinion.
In my opinion, you shuoldn't buy tires based soley on its treadwear rating or warranted milage. Tires are going to last you how long depending on how you drive your car, period. You could have 600UTQG rating but the tires will only last 30k miles because you autocross or brake late or drive fast on corners or drive spiritedly on the twisties.
Tirerack is a great place to read user feedbacck and reviews on what people thought of tires. Many people seem to like bridgestone tires after switching to them coming from the XGT H4.