Best PSU for my Rig

650 will be perfect the seasonic X-650 is the best 650 you can buy

You can use much smaller but pricewise, there's ittle to be saved by buying less than 650 watts. If ya not overclocking, I'd recommend the EA-650. If ya are, the X-650.

650 watt power supplies. For comparison purposes , the list below contains performance ratings (10 scale) at jonnyguru.com / prices as per newegg on 12/31/2010 and ones w/ double asteris (**) made it onto silentpcreview.com's Editor's Choice List:

Note: Just because you see a brand name on this list, never make the assumption that their other lines are of matching quality. Silverstone for example has other models w/ 6.0 and 7.0 ratings.

Antec Signature 650W (10.0) OOS **
Seasonic X-650 650W (10.0) $135 **
Silverstone Olympia OP650 (10.0) NFS

Thermaltake Toughpower QFan 650W (9.5) NLA

Antec Earthwatts EA650 650W (9.0) $50

Antec True Power Trio 650W (7.5) NLA

XFX XPS 650W XXX Edition Power Supply (7.0) NFS

Antec NeoPower Blue 650W (6.5) NLA

BFG BFGR650PSU 650W (6.0) NLA

NorthQ Black Magic Flex 650W PSU (5.0) NFS

could i get a much higher psu wattage which would allow me to upgrade and run queiter?

Seasonic X650 best but most expensive option, some money savers.
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

If you know what you will be upgrading to otherwise how do you know what you'll need?