The integrated/modular debate has been flogged to death on this forum with all those of vintage years & experience stating go modular for a number of reasons. If you or anybody is thinking of eventually going commercial then do a full PPL to start with. If you hold a PPL you would get very little credit if you were to switch to integrated. So get the PPL upgrade, re-validate your Class 1 and follow the relatively safety of the modular path where you control your rate of progress.
Your age is not a problem, seen many a student of similar age & older (both integrated & modular) go on to a successful flying career. If you fully FOCUS then you could be all done within a couple of years with a 30+ year career ahead of you. You shall find the ATPL theory be it distance learning or full-time the most time consuming & least motivating part. All the best.