I would definitely suggest getting a desktop for Dolphin, and having a laptop or tablet for everything else that you need mobile. A really good GPU is not necessary for Dolphin, the 750 TI will be excellent unless you want to run crazy IRs or something. You want to invest more in the CPU, for which I would suggest getting an i5 4690k, better OC and significantly better performance.
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
