I wasn't wrong, I was given the wrong information and I noted that I was basing it on what I was able to find since nothing had been posted at the time.
The mobo is micro ATX sized, not similar to the other Slimline models I looked at which only had two RAM slots and PCI slots on odd sized boards. No, I din't take the time to flip through all 50+ listed on HPs site
The first list of features said the CPU was a dual core, which was misleading.
The request for the low profile is moot if he buys a midsized case, and since the original post was looking for something around $100, which would rule out an additional power supply taht would most likely be necessary but impossible to tell since HP doesn't list the wattage on their site either.
So in the final estimation, you may or may not need a power supply to go with it but you would have to check to see if it is labeled and if it has the appropriate additional plugs if needed. If no plugs, go with the ATI as it will be powered through the mobo for comparable performance.
(and maybe some around 100 dollars too)
the only issue will be heat really. if it requires it i will mutilate his case just to adjust for it, lol.