I am looking for opinions on the variations of hammer (Brass/Nylon) etc. Brands vs quality vs cost.

links welcome.

Just buy whatever you want from Brownell's and you'll get the best quality/price.  The hammers they sell are specifically made for gunsmithing.

Other than that, you can go to any better hardware store and buy good quality nylon hammers.
Brass hammers are harder to find, so that's why you go to Brownell's.

Make your own

What are you hammering?
A FSB on an AR might take a differant hammer than a FCG

You will end up needing several of each type.



I keep two different sized brass hammers and three different sized Nylon hammers at my desk.



I also have a leather hammer, ball peen hammer and a deadblow hammer that occasionally get used.



As was mentioned earlier, check out Brownells selection of hammers: http://www.brownells.com/gunsmith-tools-supplies/general-gunsmith-tools/hammers/index.htm



If your just starting out you can find nice mid-sized hammer that has both a brass and Nylon face.