I'm also a large cyclist. Definitely right on with the higher spoke count. Further, look for a good, sturdy rim. I would never get anything that isn't double-walled.
The first thing to do is go somewhere with experienced bike techs. Chat with them some. Try to get a feel for where they really care. Explain what you want and what your concerns are. Be prepared to pay a little more for better quality. Also, be willing to wait if they need to order something that's just right.
I've had very good luck with REI. In years past, I had great experiences at Pittsburgh Pro in Squirrel Hill. My last couple of trips there were deeply dissatisfying, though, and I don't think I'll be in a hurry to go back.
The folks at Gatto out in Tarentum seem pretty nice. I haven't actually taken my bike there for any work, but I've bought accessories there, and they were very helpful, and were more than willing to spend time helping me pick things out, even when they were not expensive or high-end.
I would avoid the new Performance location in East Liberty, at least for now. I checked them out this weekend, and so many of their people are new and inexperienced that it seems like it'd be a bit of a crap shoot. What you want is someone who knows what they're doing.
I don't know if any of that is helpful. I hope so. FWIW, I've been able to get wheels that last for years at a time with daily use.