Was your plan to replace the AE Modular or to add the Eurorack to it? Honestly, I think your AE Modular setup will cover most of the ground your proposed Eurorack system will cover. I would say that unless you just really want to try specific Eurorack modules that are different from what's in your current case, you're probably fine for now. I would recomend a couple more LFOs or whatever other modulation Tangible Waves offers and just looking up patch ideas. The quantizer and Ornament and Crime (if it comes back in stock) are also available in AE, and would probably help as well.
edit: I do have a Polyend Tracker as well and it is a great controller/sequencer for modular. If you get a MIDI module for your AE Modular, you can work that in easily and absolutely use that setup to do melodic bass and leads using your current modular, with other samples/sequencing/synth stuff being done on the Tracker or a DAW.