Some please help me pick out the best service among those mentioned on the site.
There is no 'best'. Certainly not in that group. Missing at least two excellent choices.
I'd skip the EB MVP. Overkill. The Valeton isn't bad, but it's cheap and can be found under different brand names.
I didn't like the feel or throw of the Mission Engineering pedals. I like the feel of the Ernie Ball VPjr, but replaced it with a Dunlop DVP3 when I got the Kemper. It'll work as both an expression and volume pedal. The Boss is solid, but volume-only.