setup help

[madmack1]

hi i have a sapphire 7770 hitting 180 khs
was a bad initial choice for mining (still an upgrade from my 4730 lol)
 can i mix this card with my 7770?
http://rover.ebay.com/rover/0/e11060.m43.l1123/7?euid=dda3291004b64860a88d34b2d0382300&loc=http%3A%2F%2Fcgi.ebay.co.uk%2Fws%2FeBayISAPI.dll%3FViewItem%26item%3D151201545807%26ssPageName%3DADME%3AB%3ABOC%3AGB%3A1123

I have i7 clocked at 4.2ghz , can reduce if needed
500w psu
6gb corsair ddr3 ram

If i buy this card can i mine with them both? should hit 780khs then combined

OR THIS ONE

VTX3D AMD Radeon HD 7850 2GB X-Edition Graphics Card