Excellant question from Stephen, as the two may have drastically different needs.
I recommend NOT to mix your business system with your personal system. If something were to happen to the system while "entertaining yourself" (I know, that sounds bad, but David's words), you may be out-of-business until the problem is corrected. The security risks are not worth it.
Not to mention, how are you going to handle the IRS and your business expenses? Good luck seperating the two. Even if the deduction is approved or denied, you will have opened the door (and red flagged yourself) for audits. Don't do it!
For the price of systems now-a-days, just get two systems.
Btw... I haven't purchased a computer/component in a brick & morter store in many years. I find better deals on-line. Most of my business goes to
www.newegg.com . Other places I shop are
www.tigerdirect.com ,
www.retrevo.com and a couple of others.
Oh... and there's no need to custom build a business computer, except for adding the software you want to run. A business class computer is more than sufficient for this business.If you want to custom build, and you have the skills,
www.tigerdirect.com has some great build-it-yourself kits at great pricing for your gaming computer.