You want to BUY a computer that will do all that? No.... *shaking head*
You need to BUILD one. You can build one for under $1000 that'll do all you want and more.
It is VERY easy, "I don't possess the skills..." Yes you do, everyone does. I promise, once you do it, you'll wonder why people buy pre-built computers it's so easy.
Things to keep in mind:
*The Power Supply, Motherboard, and case must all be of the same form factor, ie. ATX
*The first thing you should pick is your processor, build the rest around that. The processor will have a certain socket type. Once you pick your processor, look for a motherboard that supports that socket type and find the one that fits your needs best (connections, etc..).
*Now the mobo will have a form factor, ie. ATX. Look for a case that will hold this mobo, I suggest an Antec Nine-Hundred, great gaming case, tons of room and fans and quite. Also some cool blue lights in all the fans.
*After you pick your case, pick your power supply. Make sure it supports the proper form factor. Also pay attention to where it mounts in your case. If it is top mount, make sure it doesn't have a top exhaust fan, otherwise you'll be cutting a hole in the top of your case. Also, get at least a 850W one.
*Now you've done all that, you can start looking at your video card/cards. I'm sure when you chose the mobo you picked one that has a PCIexpress x16 slot or 2, so find a card/cards that work for you. Some mobos support hybrid SLI, with Vista and Windows 7 only though.
*Finally look for a sound card if you need one.
Now that this stuff is taken care of, you can either plan on swapping your old DVD/CD drive/drives and/or hard drive/drives into the new build or if you want to buy new ones.
If you decide to build one, you can PM me when you order all your parts (it could take up to a week for me to see the PM) and I can give you more detailed info about assembly.
I encourage everyone to build their comps and stop giving money to these garbage companies like Dell for overpriced, proprietary junk.
Newegg.com is your friend!