I suggest that you join the Samplitude Forum and do a search. There are many controllers that work with Samplitude and there are threads and tutorials (by Kraznet on YT) on how to use them.
The ICon series isn't perfect, but good hardware and quite usable. I use the ProX and really like it with Samplitude. On the user's forum I gave a full review more than a year ago.
I recently have got Alesis MasterControl and it is working as expected. I didn't need any adjustment on Samplitude but just selected the "Samplitude" preset on the device. I don't know any other devices that have optimized preset for Samplitude. The only issue I found is that I can't switch the function of the rotary encoders (pan pots) but this is not critical.