You sound like the perfect candidate for a Helix. All the amps in the Catalyst are now in the Helix too, with none of the limitations you have mentioned. If you love the sound of the Catalyst you can always run your Helix through an amp and cab- after 8 years I have finally found my Helix Dream Sound by running without cab block into my tube power amp and cab (for monitor) and with cab block (and a few voodoo tricks) to FOH. I would personally not advise using a Catalyst AND a Helix because you already have everything and more inside the Helix. (you could always just use the FX Return on the Catalyst and that makes it your power amp). Yes, the Helix is way more expensive but after an 18 month detour into the Kemperverse (loved the sound, hated the UI and limitations) I bought my way back into a Floor AND a Rack - for a total cost of €2000 (used). Good luck!