First of all, make sure it's got a PCI-E card in it and not an on-board. You DO NOT want onboard video. Even if it has a PCI-E slot in addition to the onboard video YOU DO NOT WANT ONBOARD VIDEO.
OEM vendors under-rate their PSUs (actually more accurately, 3rd party PSU makers over-rate their PSUs). It'll be dicey, but that onboard PSU is probably closer to a 350w Antec in actual ratings and should work fine. HOWEVER be aware that HP systems are notoriously un-expandable.
Frankly I'd recommend a Dell E510 which has a better chance ofl supporting an X800 Pro. And they'll come to your house and fix any failed hardware for free for a year. If it was me, I'd rather own a Dell than an HP any day. I've seen inside both of them.
The CPU may seem slower, but in actuality this system will probbaly be on-par with that HP. HP uses some really performance crippled mobos on their systems. They trade off performance for stability.
I just priced one out for $720 before shipping and tax.
Go here:
http://configure.us.dell.com/dellstore/ ... 51F4&s=dhs
Don't freak - the base price is $974 but that's with a monitor and TV tuner card.
Now select the following features:
Intel® Pentium® 4 Processor 630 w/HT Technology (3.0GHz,800FSB)
Operating System Microsoft® Windows® XP Media Center 2005 Edition
Memory 1GB Dual Channel DDR2 SDRAM at 400MHz (4x256M)
Deselect the TV tuner and remote
Keyboard Dell USB Keyboard
Monitor No Monitor
Video Card 128MB PCI Express™ x16 (DVI/VGA/TV-out) ATI Radeon X300 SE HyperMemory
Hard Drive 160GB Serial ATA Hard Drive (7200RPM) w/DataBurst Cache™
Floppy Drive and Media Reader No Floppy Drive Included
Mouse Dell® 2-button USB mouse
Network Card Integrated Intel® PRO 10/100 Ethernet
Modem 56K PCI Data Fax Modem
CD ROM/DVD ROM Single Drive: 16X CD/DVD burner (DVD+/-RW) w/double layer write capability
Sound Integrated Audio with Dolby Digital 7.1 capability
Speakers No speakers
No Productivity Suite - Corel WordPerfect® word processor only
No Security Subscription
Hardware Warranty 1Yr Ltd Warranty, 1Yr At-Home Service, and 1Yr HW Warranty Support
Oh, and they give you a free printer. This deal is only valid until midnight this Wednesday.
If that's too soon for you, check this site on Thursday morning for next weeks unadvertised specials:
http://www.gotapex.com