What physics course(s)? And, will he be taking higher math courses, too (like calculus)?

For the first two or three semesters of intro physics courses (mechanics, E&M, modern physics), anything with scientific notation, trig, and exponential/log functions should be adequate. Square root and square are mighty convenient, too!

I used to teach both algebra- and calculus-based intro courses and I never used, nor expected my students to have, anything more complicated.

In the HP line, the new 35S should do nicely.

I took calculus back in the days lo-o-o-o-ng before calculators and managed quite handily. The fancier HP and TIs are apparantly thought to be almost necessary for such classes now, though. Others here can comment on that.