GoPro Hero 3 video editing desktop PC build

I'm looking to purchase or build a tower PC that will pretty much be used to edit videos that I've been taking with my new GoPro. My old tower won't even play the videos smoothly, so editing them is a definite no.

I use a laptop at work and I'm on it all day, so the desktop PC will only be used once in a while to edit gopro videos and maybe the occasional light photoshopping. Keep in mind that I'm not doing professional editing, it's just recreational. I just don't want to be stuck behind my monitor waiting for an extremely slow computer to process.

My budget is going to be between $500 - $800. I don't have a copy of Windows, so if I build one this will have to be included in the cost. For this reason alone, I'm leaning towards buying one already built. I don't need a monitor as I already have one and can update that down the road. I'd also like the ability of hooking up 2 monitors if possible.

Also, this PC will never be used for gaming. I'm a console gamer and barely have the time for that anymore so my main concern is being able to edit videos without pulling my hair out.

Does the computer link below look like something that would work for me in my price range?

http://www.newegg.com/Product/Product.aspx?Item=83-258-020&SortField=0&SummaryType=0&Pagesize=10&PurchaseMark=&SelectedRating=5&VideoOnlyMark=False&VendorMark=&IsFeedbackTab=true&Keywords=%28keywords%29#scrollFullInfo

I haven't built or bought a desktop in a long time so I'd love to hear any info you guys have to offer.