ok...
so you have 176hp - 5 for the rack wart, 20 for maths and 12 for the quad vca = 139hp spare... plenty of room... for anything...
high end big modules - take a look at the strymon magneto and starlab... magneto also includes a looper and a sampler...
mid priced small modules - happy nerding fx aid (I'd go xl for the extra modulation and slightly better ergonomics) or the newer alm fx module - or the endorphin.es milkyway or the erica pico dsp - most of these are built on the same dsp platform - I'd go for the fx aid myself as its more flexible being updatable - but may be difficult to source due to the war...
lower price modules - there's a few spring reverbs available - frequency central and doepfer come to mind - and a some bbd delays - again doepfer...
personally I think I'd try to stick with the pedals and spend the money on modulation and utilities for the rack... & maybe a different type of filter - wasp or sem (doepfer are decent, especially for the money) or go with (wait for) the fx aid xl...
have fun!
"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