Maths is way more than 2 LFOs/EGs - it also has a mixer/attenuverter section that is really useful and take a look at the Maths Illustrated Manual for patch ideas
Data takes up quite a bit of space in a small case - I'd go for the tiptop Mantis instead of the Rackbrute - about the same price, but more space and no annoying power input module!!!
Other than that I would add utility modules - the dull polish that makes the shiny modules shine brighter - which are a fundamental part of a modular synthesizer that most newbs forget as they don't understand how to patch yet so fill their cases with expensive modules
"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