get a good 4 or 5 point harness and you wont need the air bag. oh and wear a helmet and the HANS device if you plan on crashing you wonder why race cars dont have airbags... they can be dangerous.
as for the wheel... im not a fan of tenzo, its kind of ricy if you ask me. try a momo. or at least a sparco. something made in italy not china... but thats just my opinion.