balsa - i like the spads idea for a senior project as well... it's got all the right elements, build from scratch, durable and definitely faster than 15-20. but it's dangerous, too.

if you are settled on an ARF, i suggest the multiplex easy star as the best bet for numerous reasons

1. it's safe since it's foam and the propeller is in the rear out of harms way
2. it's big and easy to see in the air and glides well
3. it's so darn easy to fly. if you've driven an RC car, i can almost guarantee that you can fly the plane given a huge huge huge field and the first flight with someone with experience
4. the RTF takes 30 minutes to put together with 20 of it making sure the stickers are in the right place. and since you do absolutely nothing that determines the performance of the plane, there's absolutely nothing to screw up!
5. it comes RTF or ARF depending on you
6. it's fairly durable and easy to repair
7. you can modify it

i would recommend the following:
easy star kit $60
20amp esc - $25-$30
futaba 4YF with 4 Servos - $120
batteries 8-Cell 9.6V 4/5SC 2000mAh NiMH - $25 (2) - $50
half decent peak charger - $30

grand total - $285

sounds like a lot compared to the $175 RTF price but it's well worth it.

after making it, you fly it with the three channel set up first then you can modify it with larger elevator and larger rudders. then you can cut out ailerons and install an additional servo in for full 3 axis control

another one i'd look at is the sky scooter, which is a little more challenging but faster and more acrobatic.

yes the slow stick is nice, too... but i'd for the SPAD for a challenge and the Easy Star for a lot more fun.