@Mr_M There are good and bad things about buying from a company.
Good: You get support, a tried and true setup, and they combine everything for you in a working package (it’s easy).
Bad: They are much more expensive than doing it yourself. No satisfaction of completing something yourself. They’re far less customizable than an original build. Did I mention they’re expensive?
Building is actually pretty simple. You just need the basic parts and an understanding of what’s needed, where they go, and what’s compatible. It does require time and effort which is why Dell and other computer building companies exist and take your money.
Personally I’d avoid HP, but that’s just me. I’ve had multiple bad experiences from them regarding computers (an HP Pavilion desktop that was the worst computer I’ve ever had the unfortunate privilege to use, and an HP Latitude Laptop that broke every 3 months or so).
As far as quality goes I’d suggest Dell if you’re going to buy from a company. They have a very good track record and I’ve been using school bought quality Dell desktops for the last 6 years or so. Their XPS desktop using the best hardware available for customization is $2000 as well (this is with a 1 Terabyte hard drive….since you want lots of music space….it’s a bit lower with a 750 gig HD).
Definitely take some time and shop around. Pricegrabber.com and Slickdeals.net are great places to find info on good deals as well.