Hi CruizCuz, welcome. I know it sounds like a tricky choice, but I'd bet either choice would be fine.
First to address your question about luer lock vs proprietry: I really don't think there is any reason to worry about this even slightly. There is a good range of both avaliable (and most are the same sets just in different versions). I have never heard a genuine point against either in practical use - I use minimed and it works just fine.
The main objection is philosophical, that minimed went with their own standard instead of one shared by others. Now I don't claim to be able to clearly understand what is kosher or not in the all-round cut-throat world of pharmaceauticals - but if it somehow really gets your goat that minimed didn't stick with the standard, well, then you might have a problem with them. But, I just would not worry about it in practical terms.
I can say I've been very happy with my mm, but from reading people's experience with Animas, I'd probably be very happy with one of those too. The Animas has full waterproof status, which could be a boon. Then again, it depends if he is likely to want to swim with one on. I swim, and I wouldn't want to take my pump anyway, personally. You can usually be off one for about an hour at a time. The mm is "water resistant" and I believe if you fell into water and it stopped working it would be covered (not sure though: that's one to check with the rep).
Of course, the BG tester integration with the ping is something to look at. Likewise, the current availability of CGMS (constant glucose monitoring system) for the minimed is also worth at least thinking about.
Each do have a few quirks and issues. It's hard to say what might be an issue until you actually try it (like the fast bolusing issue, which would have been a huge issue for me I must say - I need it slow as possible).
Support wise, I can only speak for mm, I find they can be a bit curt on the phone, but they come through with the goods quickly. A button stuck on my pump and I had a replacement in about 12 hours. I thought I was having some issues with some sets (not sure if I was or not) and they sent out a replacement pack. They can be a bit robotic in conversation but with a bit of persistence I've been satisfied in my support needs.
Hope that's of some very small help, though I know it doesn't provide clear answers. Again my overall impression is: either would be a good choice.
One other thing: I know it seems small, but the slimline clip that comes with the mm is truly perfect for clipping the pump into the front pocket and forgetting about it.