please help ... PSU decision

[JoeJ615]

im upgrading my 9600 Pro and ordering a X800 Pro AGP tonight online .. i need a new PSU to go with it though so i need opinions on the PSU's im looking at .. i've never installed a PSU and really dont know much about them other than that the customer service guy at ATI's 800 number said i needed a minimum 300W PSU with 15 amps on the 12+V rail (currently have generic Raidmax 420W w/ 13amps on the +12v rail) .. so im looking at a couple of PSU's at zipzoomfly (yeah i know newegg rules but they charge tax in my state + shipping and zipzoom doesnt charge me tax and has free fedex 2 day lol) there are a ton 300W+ in my price range ($50-$60) but most dont have the details as in number of 4pin molex connectors etc etc .. so these are the main 2 im looking at ...

http://www.zipzoomfly.com/jsp/ProductDetail.jsp?ProductCode=374000 or http://www.zipzoomfly.com/jsp/ProductDetail.jsp?ProductCode=373044

if you guys could please reassure me that these will run a X800 Pro AGP card ... or if not please link me to a $60 or under PSU at zipzoom (or newegg but please compensate for sales tax and shipping) that will run it also like i said i've never installed a PSU .. i have this ATX mid tower
http://www.newegg.com/Product/Product.asp?Item=N82E16811156140

are ATX power supplies and ATX cases universally interchangable? or might i run into problems mounting the PSu in the case?

thanks in advance for any help ... please give your honest (and speedy lol) opinions, as i said im ordering this tonight so i'll be checking this post before placing my order

 

[Mr. Switch]

either one of the ultra's will work fine. i'd go for the first one listed just to lower your electric bill, but it doesn't matter. either one will work.

 

[JoeJ615]

thanks