Worth buying? and questions

http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=6273966&CatId=5138

if so would anything need to be upgraded on it before i start using it?

i've alway used amd computers is there a better one between say an amd quad core and an intel 2 quad core?

http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=6077237&CatId=5138

this computer pops up randomly on the site being available, should i buy this one or wait for the amd?

im nervous buying a prebuilt computer because i've had alot of problems with them (video cards frying, motherboards frying, harddrives dying ect)

is there another good site to get good deals on computers? i dont got a whole lot to spend and would like something i wont need to throw away for a long time and also to have the option to upgrade in the future.