i7 or later generation i5 CPU's are what you need to run Dolphin. Avoid AMD processors, Dolphin utilizes 2 cores (possibly 3 w/ certain settings), no more. Intel has superior single-thread performance and therefore runs Dolphin better. 4-6GB is fine, 8GB if you want to run anything in the background. GPU isn't a huge issue unless you run high res.
Arch
Intel Core i7 - 4510U
iHD4400
8GB RAM
Check here first:
wiki.dolphin-emu.org
Intel Core i7 - 4510U
iHD4400
8GB RAM
Check here first:
wiki.dolphin-emu.org