Advice on building Computer/Buying one.

So last week I got my HP DV6T and the AMD Card failed so I got a refund. After all that I thought maybe I should get a Desktop as I need power to a certain extent. My main reason for not getting a desktop in the first place was due to myself going to Flight School next year to do my ATPL etc I wont be able to take it and wont really have time for a Computer but I thought maybe I should just get or build my own then just get a Macbook or something for Flight School.I looked at some of HP's Desktops and like the looks but I hear the mother boards aren't that good? Also what would be the cheapest option? My budget lets just say $1000.I need it for Video Editing and I'd like at least 60FPS on FSX with an Addon Aircraft like the PMDG 747 or 777 when it comes out with some addon scenery and REX. I don't have my sim on Ultra High though I vary my settings.. I was thinking maybe something like:i5 2500K 3.3GHzNvidia 5508GB RAM (Probably boost it too 16GB after a couple of months)1TB 7200RPMNever personally built a Desktop so not sure how easy it will be. Not really sure on Mother Boards etc so I'd need pointing in the right direction for that. Probably get most of New Egg as I hear it's a great website for this stuff.Any advice would be appreciated! And I hope this isn't in the wrong forum, if so sorry!!Cheers