Here is how I have seen this type of project done successfully:

Spilt the class into teams of two. Have each team purchase an inexpensive kit - you can get group discounts if you contact a company like Tower Hobbies http://www.towerhobbies.com/

Here are a few good choices:

http://www3.towerhobbies.com/cgi-bin...?&I=LXDJC3&P=0

http://www3.towerhobbies.com/cgi-bin...?&I=LXJ596&P=0

http://www3.towerhobbies.com/cgi-bin...?&I=LXM399&P=0

http://www3.towerhobbies.com/cgi-bin...?&I=LXFG09&P=0

Once they are built, arrange a day with your local club when you can take them there and have the club members test them.

BTW, most clubs will be very willing to come to the classroom to help out any way they can. As you can see from this thread, we are more than anxious to share our hobby!