What would happen...

Hello,
I have a couple of simple question (If you know more about pcs than me, which im pretty sure you do )
1)what would happen if i insert one of these graphic cards
http://www.newegg.com/Product/Prod [...] 6814161363
http://www.newegg.com/Product/Prod [...] 6814161348
into this systemm..
http://www.dell.com/us/business/p/vostro-460/pd
With the i7-2700 CPU, 8GB RAM, and a 350 Dell power supply..
2)will it damage the hardware or will it run decent?
3)and can i actually get a higher Dell power supply that will able to run the system?
4)and if not, what would be a good graphic card that is close to the HD radeon HD6850 that would run on this system?
thanks..

The psu which you have will not run this card.
Get a Corsair 500w psu
http://www.newegg.com/Product/Prod [...] air%20500w
a higher psu is recomended but this will be just enough for youif you do not do any overclocking
http://www.newegg.com/Product/Prod [...] 6817139020
this is a very good option for psu upgrade

Dell does use good PSUs and tends to rate them for continuous rather than peak usage like most. The 6850 might work in that system without a PSU upgrade but you would be pushing it...
I believe your computer should be able to use any ATX PSU if you want to upgrade it. This would be a good choice for $49.50 and easily handle the HD6850 or better cards;
http://www.newegg.com/Product/Prod [...] 6817371047

It is an overkill I know, but he don't have to upgrade his psu again and again in future.
And I know that Dell psus are rated for continuous power but do you have any idea about the amps on +12 v rail?
This was the reason why I thought a PSU upgrade will make sure that nothing goes wrong, and I am against pushing PSU to limits as it can get unstable depending on the temprature

So just to make sure, I can infact replace the powersupply on the dell vostro but i have to find one with similar dimensions?
I've been looking all over the internet just to be sure but everyone says a different thing..well, i dont know why Dell doesnt have their own replacement PSU's with higher supply for their systems.
thanks for the help

Right, check that cabinet and get the form factor of it..