Xps430 video card update for cad cam

I have an xps 430 with 6gb ram and it has an ati Radeon hd3600 video card

in it. I'd like to get an Nvidia quadro 2gb card or a firepro 2gb card I've been told you can't use the full length cards as in 10or 11 inches long because the card fans blow heat into the cpu cooler area and it is also a stock power supply.  I know a bigger card will need a bigger power supply

So 1 what cards can I up grade to and how much video ram can I have on the card.  2 what size power  supply should I get and how many plugs should it have. I remember being told I could only use one style of card because of the position of the slot vs cpu cooler unit. 3 do I need to stick with the firepro v4800 style card size which is I think 6.5 inches long.  I've seen photos of full length cards in the xps 430 but does it kill the cpu with heat. I don't want to blow money this is what I have I just want a vector graphics card in it cheap and working ok.