Only reason to clip a horse is if it is likely to get a chill when drying off after exercise. If your horse does not sweat too much doing the exercise you do then there is no reason to clip him.
As for what clip - doesn't matter what the horse looks like, it depends on the amount of sweating it does!
Thats the problem he does at least half an hou a day of work but he gets Very sweaty!Should i be concerned i mean he is a bit chubby but not very but he does sweat mostly on the neck and breast... so yer...
Go for a chaser or trace and see if that helps then if you need to take more off you can the next time, easier to take more off than prittstick hair back on!!! LOL
As said, take off the minimum to start with, and see how he goes, maybe a bib, or bib and belly to start with. I've got a clipping guide on my website if its any help !