Hi, as a former Electone EL90 player for many years, I would recomend another type of module that is an arranger, the choices are: Ketron XD3, Midjay, and if you can find a used Roland RA95-800, Korg I40 or something like this.
I hope it helps you. I did use my EL 90 with the Rolands RAs and the Ketron X1 and SD1, and I know that the modules by Ketron will do just fine.