I know that Prairie City Kart Track is exploring the addition of 80 Shifters to their program. Contact Darci at firstname.lastname@example.org and express your interest, I am sure it will help visualize the potential of doing this.
As for 125’s, unless that population of local racers grows they will likely run at the back of an 80 field. In any case most racers will want to encourage that, as Ben pointed out, that the equipment is safe, but, from a competition standpoint, the engine package will need to be legal. If not, the series you hope for will empty like a bar at closing time.
Best of Luck