Should I choose kickboxing or karate (shinkyokushin)?

If you haven't already go for a trial run with both schools and decide on the better one that way.

On a further note I'd be asking about if you can join in the Karate school's 35+ classes regardless of your age, if not there's only three classes a week available to you which isn't much.

Visit them both and decide which teacher you'd rather train with.

It's really what ever you are trying to get out of it if you want to learn self defense the go for the shinkyokushin karate but if you want to compete or go into mma I would say kickboxing but if you can't pick one look for dutch kickboxing it's a mixture if both shinkyokushin and kickboxing/muay thia but in all honesty it's what ever you really want to do

"Kickboxing" doesn't require belts, just gets you right in there.

if your a bigger guy i would say karate will capitalize on your power better kick boxing will make you more well rounded its up to you.

but i think karate!

(also with gas prices the way they are saving yourself a drive aint a bad idea either)

i do muay thai which is basically kickboxing but more aggressive there are hardly any grapples but as for punching, kicking as well as knees and elbows VERY effective