i think you should post this in the hardware section. (:

u'll get better opinions over there. or you could head over to www.goldfries.com and use the pc buying guide. really good reference guide. the prices are abit outdated but the specs still apply.

IMO, go for intel. and you can probably get a motherboard with an onboard graphics card so you dont have to worry about spending extra cash on the graphics card. (;

if you're really tight on budget then use the given PSU with the casing. but i'd suggest you get a good psu. probably a coolermaster or acbel or something. around 450w. will be about 120 bucks.

im assuming you've got the other peripherals as your dad's pc will also have those things so you'll only have to rebuild the rig.

any reason why you're interested in a 24" with HDMI? want to play ps3/xbox? haha..

btw. one of those 24" with HDMI is gonna set u back probably 1200 at best i think.. probably more. not cheap.

cheers.