OM: Kingdom of Sand

For the strings, there's a couple of free soundfonts that really sounds good.
One is at

also, there's a free collection of soundfonts at

If you want to create your own drum parts, check out nskit at
they have a nearly complete drum kit as a soundfont and it sounds 'live'. just check out the demos. I mainly used this kit for my drum tracks.

btw, try out Sony Acid to do loop editing. You can use sampled drum sounds like at