This is the vacuum pump I own:
http://www.thetoolwarehouse.net/shop/ROB-15234.html
I'm not saying the other ones aren't any good or this one is better. All I know is it works great on cars. If you want something that will work on a home AC system you probably want some more CFM. Depending on size I would say a 4 cfm would do for just about any residential unit.
As far as gauges that gauge set is fine. You don't need the most expensive one. Sometimes simpler is better.
Danny