Thanks again for all the info guys.
I ended up going to another locksmith who seemed to know a lot more about Mul-T-Locks than the previous guy (when I asked that first guy why he recommended the Classic and not the MT5+, he claimed "the only difference between them is the price and the key").
The second locksmith recommended the MT5+ and explained why, and it all made sense and sounded like he knew his stuff. So, I went with the MT5+.
The only thing I'm still unsure of is the strike plate. This locksmith didn't seem to think I'd need anything more than what comes with the MT5+, which is more of a strike box I guess (and 2.5 inch screws). And I assume the fact that it gets screwed in from inside the box makes it more secure than a typical strike.
I guess I'm just wondering if that's secure enough or if I can/should still do better as far as kick-in protection goes?
Thanks again.