Hmmm...
I would recommend...
Replifex, even better with an Intellifex as well. Each has strong points, but everyone has their own tastes, so who knows what might shine
Digitech 2101. Yep, the predecessor to the 2112 and 2120. It was actually a superior unit in many peoples' opinions. I have owned all three, and preferred the 2101. But, I also loved my ART SGX 2000/Express, so my opinion might not be the best
One of the Lexicon units. Maybe an MPX G2? Good stuff.
I prefer units that have a full analog front end. For me, converters (ADC) up front ruin the feel. FOR ME. Psychological or real, makes no difference. I feel it, and that's that. If you are cool with that, then doing a unit that can do the 4-cable method (into unit, out to amp, then FX send to unit and return back to amp) might be best, as it allows you to do both pre- preamp effects, as well as post. Or, pedals up front and the unit in the loop.
Any unit will color, unless it utilizes a true bypass, or you create that. If an effect is always on, then that will not matter. For recording, simply pull the unit for "true bypass"
IMO, it is a matter of finding gear that reacts WITH you. Like crayons, chalk, charcoal or a simple pencil, these are tools of art, and WILL alter the sonic landscape.