Re: what type of computer would you recommend
Custom built is easy(ish) and the way to go, you can make a decent computer for $1,000 but if you are not looking to build let us know, so we can properly instruct you from there (While it would not be as specialized and personal, you can get by for editing with a store bought computer, as long as it is small scale (IE: Not your profession you do for a living (ideally))). (Wow, that was allot of brackets)
Some advice I can give you regardless of which path you choose is, you need a computer with a big (~1tb or more and fast, 10,000+rpm) hard drive (Cheap these days) as well as a computer with a good and quick processor (when it comes to intensive video editing, the processor is actually more important than the graphics card (usually) because it is what is responsible for rendering the frames and such, so a good processor will give you quick render and load times. If you are using it for only video editing, you can get away easy enough with a lowish-mid-grade video card ($90-$120), however if it is HD video you are working with, or if you will be doing much gaming, I would suggest a better gfx card (~$120-$200) (Special Note* You can not really judge a graphics card by the price, I use that as a LOOSE (cant stress that enough) reference point).