Three days ago I modified an old Madcatz Xbox steering wheel. I made a lever from MDF and mounted it where the steering wheel used to be. I think strengthed the springs on one side(the direction you pull) and replaced the other springs with wire so that I could limit the rang of motion in both directions. It isn't beautiful but it works like a charm. I have it set up on a footstool next to my chair.
As for the speaker thing, if this 14 year old kid has access to speakers that are better than my logitechs and will function better when connected to his computer, more power to him but I can't even find info on these speakers he mentioned. Believe me I know my Z-5500's are on the low end in the audio reproduction big picture but as far as functionality, looks, sound and reliability go I don't think they can be beat.
I will try to get some detailed pics of my handbrake setup ASAP. It was about a 3 hour project from idea to tweaking in LFS, definitely do-able by sam93 and his father.