I would look at something like FX Aid XL which will give you lots more effects in fewer HP...or have a look at the Versio series from Noise Engineering. Nice that you can easily switch out firmware to any of the others that they have available.
Don't see any sort of filter in your rack yet...Doepfer Wasp or TipTop Forbidden Planet are good smaller HP filters
Disting EX may also get you some good mileage/HP in a smaller case like this
JB