104hp gotta last forever?? oh well...
hahahahaha - I thought the same with 144hp - now I have 10 times that... there's a very good reason why people (including me) always advise others to get bigger racks to start with - especially if you are going to get into DIY...
So with the current collection as above, what would your advice be for the future be? I am quite good at tinkering and know my way with a soldering iron, but not so with SMD's yet. My wishlist consists of effects, O&C, Pams WO, and someday a Befaco mixer.
first of all - bigger case - but keep this one and add 6u of 104hp - the befaco excalibus is a great DIY power supply - which should power 6u/104hp quite well as long as you stick to mostly analogue modules
O&C get the plus version - through hole diy! but will you really need it if you get a PNW? maybe... get the PNW first and then decide
effects - it's hard to beat an fx aid xl... at least for the size/price/functionality...
SMD - nonlinearcircuits or the AISynthesis SMD module are both good places to start...
envelopes and lfos would be a good area to invest in - Maths is especially good if you are more interested in learning modular synthesis instead of synthesis with modules - if you see what I mean - see the 'maths illustrated supplement' as a good jumping off point/primer for that.. Stages is also exceptional - as are batumi and zadar... also take a look at the new tiptop/buchla offerings they are very good value for money - first 2 are available for preorder!
also a filter or 2 or 3 or more - personally I like the doepfer offerings - inexpensive and do what they say they do, based on classic filters - but otherwise hit up youtube - maybe not the best quality audio, but you will get an idea of what you like don't like
at some point more vcas, more utilities - I like links, kinks, shades, veils - as a starter - but not DIY friendly! and kinks is discontinued - wmd/ssf toolbox is a good substitute - a matrix mixer is also incredibly handy...
you'll probably want another 'melodic voice at some point - again the tiptop/buchla offering looks really decent for the price
"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