Is that blocks on all four corners? Or just the rear?
You pretty much have two options. Bilstein's, or anything else. Haha.
The Bilstein 5100 is a great shock, with a firm ride. Good for a full size. Only real draw back is that they are more expensive.
Probably not the best price, but Poly is a stand up shop.
http://www.polyperformance.com/shop/...s-p-19258.html
When you talk Rancho RS5000, Rough Country Nitro 9000, Pro Comp ES9000, and the Skyjacker Nitro 8000. The Rough Country, Pro Comp, and Skyjacker are pretty comparable (Haha, that is a nice way of putting it...). reviewed as good riding shocks, and great for a budget. You can do one on each corner of your Blazer for roughly $165-$180.
http://www.jcwhitney.com/shocks-and-...estid=35726630
Honestly, you can't really go wrong with the ones I've listed. My opinion is to read a couple reviews, do some pricing, and pick the best deal.
Also- Totally my opinion here, but I'd skip the rubber boots. They always end up looking like crap, and if they rip they will just hold water.