I haven’t played since it released, but Stewie is basically a god of New Vegas modding and I doubt it would cause any issues.
Your GPU might or might not make a difference, most of the issues with performance are poor optimization and engine-level issues (that Stewie seem to have addressed). There are several more stability mods out there like Tick Fix and Heap Replacer that help, plus the 4GB patch for the executable of course.
The Viva New Vegas modding guide is a good place to look for more info, even if all you do is stick to the performance improvement stuff.