And if you want to explore sound with much more freedom and absolutely stick to a small format of 60HP, the possibilities of choice of modules are immense...
but also extremely limited...
by the time you include a power supply - usually 4hp - you're down to 56hp for actual modules... which is not a lot of room at all... especially if you want 2 extra oscillators and the support modules required to make the most of them - vcas, filters, modulation sources, envelopes, mixers, effects etc etc... otherwise you may find yourself trying to add too many very small modules - which leads to poor ergonomics (tending towards unuseable) and potentially trying to fit modules that are too deep into the case usinf standoffs - which is ugly and potentially hazardous to both the power supply and the modules...
I would suggest getting a substantially larger case - a tiptop mantis is a great starter case - best bang for buck in terms of hp/cost/decent power/manufacturer reputation - and buying fewer modules initially (& some blank panels - cereal box cardboard can be used) and then expanding the modules slowly as you get an idea of what you want...
"some of the best base-level info to remember can be found in Jim's sigfile" @Lugia
Utility modules are the dull polish that makes the shiny modules actually shine!!!
sound sources < sound modifiers < modulation sources < utilities