the bastl one seems easy to find:
what exactly are you trying to do? - maybe post a link to your rack - imo it's often better to get multiple basic modules that when patched together work how you want them to rather than struggling to find a particular module that works in a specific way - it's modular after all - and you may not want it to work that way next month, or even next patch
this is one of the reasons that bigger cases are better - there's space to add simple building block modules that can be patched together to do different things/behave in different ways - which is also why Maths beats most of the other DUSG based modules (especially for beginners) as it has the excellent 'maths illustrated supplement' as a guide to patch programming, which can be extended to patching in general!
"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