Is there really a big differance?
http://www.intowindows.com/difference-between-windows-7-home-premium-professional-ultimate-editions/
http://www.pcworld.idg.com.au/article/386085/windows_7_home_premium_vs_windows_7_professional/
apparently home can only have 16GB and a bunch of networking shit you won't care about, which is fine since 8GB is more than you'll ever need anyway
Unless you got 32GB of ram, save your money.