I did a currency check with the lad who did the 9hrs on the TV programme Spitfire Ace and he was in a similar position as you.
i.e. got a PPL and doesn't want to exceed a certain amount of hours because it would stop him getting on a sponsorship course.
My advice, once you get close to the max number of hours, start a new log book and put the hours in there. If the sponsorship deal doesn't materialise, you still have the hours.
I don't care what anybody else thinks about picking up bad habits if you have too many hours, blah, blah, blah.
What a load of b^llocks
FIS