Rifts does the "guns guns guns guns guns" aspect pretty well, but the only way to really emulate PC death in that is to reduce the amount and availability of armor... which fits well with Borderlands, in fact. You can also set it up so everyone has their one power that they can do pretty easily.

So, you might look at Rifts... or a stripped down version of it. Coincidentally, there's a Savage Worlds version of Rifts due out at the end of the year.