Quick Version, without going into deep specifics...

For something that will really make a sonic difference/improvement, it will most likely cost much more than a grand, depending...
You'll need a GOOD quality Digital to Analog converter, the more channels the better (i.e. Apogee DA16X), a GOOD quality analong mixing console, summing box, line amp, or other-type analog multi-channel mixing device, and/or a tape machine. The real benefit of mixing OOB is to use (preferrably very $$$high-quality$$$) analog electronics and/or tape to "warm up" or otherwise "colour" the sounds in a pleasing way; unlike digital, where it can sound very dry or stale, or cold, if you will.

I'd search Ebay for good small-format consoles and a multi-channel digital to analog converter. Look for brands such as MCI, Trident, Neve, API, Soundcraft, Neumann, Studer, Otari, etc.... (there are a lot of 'em, plus more obscure lesser-known stuff that sounds excellent, too) for consoles. There are analog summing devices available, but I've yet to encounter one and don't know much about them. I'd personally rather have a nice console with good usable EQ and/or dynamics. Neve and API make excellent mixing consoles and devices. But, they're VERY expensive, even used, and then you take the risk of buying junk that's disguised as such products!
Keep in mind, as well, that a lot of guys "dump" the digital tracks to analog tape (via a very high-quality D-to-A converter), most often 2" 24 track format for an even "richer" analog experience. Now, that's where it's at and where I'd love to be someday... Them tape machines are pretty affordable these days, but you also have to get luckey and find a great deal that's close enough for you to pick-up, have a tech, or know how to maintain, yo! They need attention, big time!

So, in closing, you're not gonna pass with a MX9000, man. Sorry, it's much more complex, ...if you wann do it "right" and have it make a big sonic improvement over mixing ITB, you're looking at THOUSANDS of dollars. I may have left-out some important points, but that's the short-version!

Good luck, man!

Don't get me wrong, though... I'm not saying you HAVE to spend a shit load of money, but I just don't know what kind of improvement you're going to get with that MX9000. It looks like a copied 24/8Mackie to me. Search for a good used Mackie if that's what you want.

"What do I need to go to and from my PC?? What effects rack units would be recommended? How would I go about hooking this up to a PC to record??? "

You may want to do some initial research on these subjects, there's a TON of information everywhere. A modern, fast AD/DA such as Apogee Rosettas, ADA8000, AD16, DA16, etc... There are other brands, but I know these sound great, myself. Especially if you're running a professional shop, don't skimp on the gear, man!! Good effects processors are available from Lexicon, Eventide, Sony, Kurzweil, T.C. electronics, and then there are plug-ins! ENDLESS!