you should also take a look at the recaro pole positions...i'm 235lbs and its a perfect fit. only problem is that they don't recline, but they are very comfortable, even on longer trips, you can use the stock seat belts also
http://www.aspecproducts.com/images.asp?theid=8250

 

5'11" 200, had seat custom made, and I wasn't having to deal with the confines of all the stock interior garbage that gets in the way.
Car was gutted... You didn't mention any budget, so you might want to investigate.