When wiring the shop the best way (in my opinion) is to run a large (#6) cable into the shop to a seperate smaller panel. Then run all your shop wiring off of that.
This has a lot of advamtages. This will save you a lot of wire going from the house panel to the shop. It makes adding shop circuits easier in the future. It puts a main shutoff in the shop and It puts all the breakers closer should you blow one while working. And don't think you need big amps in the shop either. A 60 amp panel is plenty to run a decent size shop with compressor, welder, etc.. Keep in mind you'l never have everything running at once. I have a 60amp panel in my shop - I've run my 220v welder, my 5 horse compressor and had the a/c running all at the same time and never blew a breaker. Of course all the big stuff is on its own circuit. And those three things have the biggest draw. A lot of people go crazy on house panels too. A 200amp panel is a waste of money. A 100amp panel is fine for pretty much any home, just buy a panel with a sufficient number of breaker slots. GFI protection ... personally I'd rather have GFI receptacles instead of breakers. This way you don't have to go to the panel to reset them.
The determining factor is the utility service. You can't safely replace a 100 amp service with a 200 amp service if the utility feed is sized for 100 amps. I have a 200 amp service in our house and frankly I'm glad we do. When I built our home garage I installed a 60 amp subpanel in the garage fed from the main panel. When I added our addition, I installed another 60 amp subpanel for it fed again from the main panel. As to brands, You have Siemens that services legacy brands like ITE, Sylvania, Murray, and Gould to name a few along with their current products. Then there is Square D. These are probably the top two. Square D is probably more available from a number of sources and would be my pick.
