This isn't my strength, but here's one suggestion:
A dedicated PC computer to do what you need will run about $1,200 or so. You can get a new Dell with a P4, 2 Gig, 512 meg RAM for about that. (and that's plenty of muscle to do what you need) Go here:
http://www.dell.com/us/en/dhs/products/model_dimen_1_dimen_4550.htm
I think CD burning software comes bundled with it, too. I have a PC, but many folks who do this seriously are Mac users. Apparently Mac and MOTU (Mark of the Unicorn) is a match made in heaven but caveat emptor.
Recording software will run about $300 - $400. You can get good stuff for less, but this price range gets you into pretty good territory. For $600 you can get into major league pro stuff (e.g. the Cubases of the world).
Do a search for posts by Spinsterwun in the last two weeks. He (she?) has posted many links to inforamtion sites recently.
You will need a better soundcard than that which comes in your cpmputer. Soundcards (like everything else) are 'you get what you pay for'.
I have an Echo Audio 'Mona' - I like it but am a relative newbie at this so don't have much to compare. It has four inputs including phantom power and mic preamps and direct monitoring, and a sound I'm happy with. It's $800 discounted at GC; it's highly likely that there are cheaper/better sound quality choices out there that don;t have some ofthe features of Mona. I never read a bad review of this card when I was looking, so thats what fueled my decision (and for $800, it better not get any bad reviews

)
I'm assuming you have all your mics for vocals and micing amps, guitars, power amps etc. etc. but you will need some kind of monitoring for mixdowns. PA speakers and stage monitors are not the best way to go.
There are two schools of thought on monitors:
1. Get the best you can afford - and best means most accurate. flatest response, most 'transparent'.
2. Get those that are most like what folks are going to play your stuff on - that way they hear what you heard when you mixed it.
My view is #2, above, but most of the 'pro' type guys here seem to prefer #1.
I can only respond that virtually every studio I was ever in or saw on TV has Yamaha NS-10s as their near-field monitors - but there are (apparently) significantly better out there.
You cna probably get away with your Peavey board to mix on. (Comments, anyone?)
So for now you're looking at probably < $3,000 or so. There are cheaper ways to go that may work well - but YGWYPF
Hope this helps.
foo