i've got over 75k miles on my mini-cats...still working fine. just passed emissions at about 1/4 the state requirement.
as long as you stay on top of the O2 sensors, and make sure they don't go bad, your mini cats will survive just fine.
and yes there are ways to delete the mini-cats, but no kits. its all radio shack DIY stuff, illegal, can really screw with your computer & cause CEL and its not necessary unless you're going to run a turbo or something.