The V-Amp serie from the same company could also be a wise choice.
Because they have more memory and they can be selected by midi:
By connecting the Ion midi out to the v-amp in, when switching program
number on the Ion, it would also switch program on the V-Amp.
So you effectively end up with the ability to save a specific effect
setting for each Ion program.
Alas, they only have 125 presets... so you would have the same effect
on Ion patch numbe X whatever bank.

There are several V-Amp flavors, for guitars and for bass. Maybe, the
bass version could be more usable by a synth...
There is also a V-Amp Pro in rack format, wich has digitial out.

The V-Amp2 wich i bought is very affordable, and for the price you
will get in the box a stylish nylon shoulder bag to carry it around.

Note: i did not try to use it with my Ion, i use it with my guitar ;)