I am not sure that flying schools can offer any sort of structured hour building other than to offer you a course of training, or to rent you an aeroplane where you go off and do your own thing. If you are in a group, use that aircraft to gain good experience by flying to interesting and challenging destinations, that way you can gain useful skill and experience, which can be enhanced by sharing with another pilot. With 50 hours PIC on cross country flights, plus a Night qualification, you can start training for the IR. A PPL with an IR is of more use than a CPL without one, and you can minimise the total hours required to gain both CPL and IR. Try to avoid boring holes in the sky just to gain hours, they are largely worthless. A few destinations in your log will look more impressive than circular trips from the same airfield.
The greatest problem for the hour builder is that they lack the knowledge to apply self discipline and end up wasting the time. They get into bad habits and then find a structured course of training hard work.