i would have to say that Monarch is the best. you configure everything and their prices and warranties are superb. i would also suggest Ajump as they sell small form factor pc's that are configurable. search for online guides on building your own pc. most people that have built their first pcs have said that it wasn't as hard as they though it would be.

you would save money by building it yourself, but Monarch has everything you need and so on.