Karting??..

No problem. I won't ever use it, but I'm not even sure if I have one anymore.
Neck Braces
Here are some that are quite a bit cheaper than a hundred bucks. I would double check and make sure they are legal in your class, but I wouldn't see why not.
Yeah I'm not going to have any problem talking my wife into safety equipment. She plans on keeping me around for a little while lol... I just hit her with a pretty good bill on all the stuff so far I just need to let the dust settle for a few minutes and then I'll get more stuff.... Lol this isn't her first rodeo with me and my toys... She's aware of the rabbit hole....