Post

You have a lot of real estate dedicated to the fixed filter bank, a very subtle module. I would consider eliminating that until you have expanded to a larger rack, and dedicate that space to VCAs that are more "hands on," the Doepfer Dual Quantizer, a sequential switch, and Pamela's New/Pro Workout as a master clock.
Also, many Doepfer modules are fairly deep so make sure your rack is deep enough to accommodate them. I was interested in the A154/A155 combination, but my rack could not accommodate the depth of the A154.
Finally, the layout you have here wouldn't be very ergonomic. Your cables will be criss-crossing and going all over the place. This is something you will figure out as you use your rack, so be prepared to move your modules several times until you settle on a layout that makes more sense. Think about how your 2600 is designed and try to mimic that signal flow as best you can.
Try to avoid 2hp-4hp modules unless absolutely necessary. You'll thank me later. It's tempting to squeeze in a tiny module to add some function that you need, but if you really want single function or one knob per function modules, bigger usually equals better when it comes to tweakability and fun. If you're trying to decide what to do with the remaining 2hp, put a blank panel there and invest in another case. It's hard to turn knobs with any precision when the knobs are tiny and buried in a sea of cables.
Good luck and have fun!