ModularGrid Rack

I'm a modular noob and looking to fill this 52hp. (I already own the stuff in it.)

Other outboard gear: Novation BassStation 2, Erica Bassline DB-01, Roland TR8-S, Novation Launchkey 25 & Ableton Live.

I'm mainly using the TR8-S for drum tracks and playing the synths over top.

Any help would be most appreciated.