Not sure about a PPL but !
A CDL is good because you won't have to pay any interest until the end of your training.
Basically make it last as long as you possibly can.
Then, the rates are quite high (in 97, i remember it to be around 14%!!) so what you ought to do is to get a personal loan to pay back the institute who lent/granted you the CDL.
That way you have save so many years of interest and you are now only paying the minimum for your loan.
CC transfer, personal loan whatever it takes, you can really keep it as low as you can go.