nice yeah unless you have the geeky instinct to sit happily for hours troubleshooting, theres allot of value in a prebuilt system with support
Personally, I've been burnt by "specialist" music production systems before, so I know they are not for me. If I were to go that route again, I know for sure I would be asking what power supply, fans, etc they were fitting rather than the usual processor, hard drive space specs that get pushed in your face. I was mortified when I saw the power supply that I had been trusting my long studio sessions too... that was from £2500 worth of Carillon PC. It did have a zalman processor fan and the rackmount case was funky for about a minute... in fact, thats all thats left now. Taking up space under our deck table.
Hope the company you found turns out more reliable than Carillon.