Any recommendation of a 6-8 inputs, 6-8 outputs audio interface?

Most soundboards and mixers have multiple inputs but most only give you 4 master outputs and any number of "sends" Recording consoles have more output capability but their price is much higher. Many "firewire" mixers have several inputs and usb outputs to be able to multitrack record on your PC. Many of these types of mixers come with software that allows you to do several types of "mixes" including 5.1 surround sound
Check with musicians friend and do a search for usb mixers and firewire mixers to get an idea of prices

Why would you have to upgrade it if all you are using is Microsoft Office 2010? Your old PC already out performs that incompatible and over priced mac garbage by the way. EDIT: If money is an object, put 2 more gigs of ram in. If you're trying to find a reason to buy a new PC, you don't need a reason. Go ahead and get one. Your old system will run any of these programming languages. As far as lag, be specific. Internet speed? Programs? Your PC is fully capable of performing these tasks without effort. You might clean the crap out of it, defrag it, etc.. Whatever you do, DO NOT be mislead by Apples bullshit, misleading ads. To make it simple, Macs are grossly over priced and incompatible with 95% of the software on the market unless you install windows anyway. Out of every 100 computers sold a day, 95 are PCs and I'll guarantee it isn't because all those people can't afford a Mac. They simply know better. Don't let a bunch off booby brained kiddies who facebook and check mail tell you they are anything special. I've been an industrial programmer for 40 years and Macs are nothing but bling.

The MOTU traveler will work fine for you.
http://www.zzounds.com/a--2677556/item--MTUTRAVELERMK3

Well... you kind of need to know what your DAW software is going to be first, since that will directly impact the interface you purchase. So pick your platform - then select an interface would be my advice.