Garrison also does the 4-finger thing (all fingers except pinky) which is worth trying. I don't use that technique all the time but it's ludicrously fast, especially if the line is fairly simple other than the subdivision.
As far as delay pedals I wouldn't overthink it for something like this. Something like the Boss DD-8 should fit your criteria and most music shops carry them.
As far as delay pedals I wouldn't overthink it for something like this. Something like the Boss DD-8 should fit your criteria and most music shops carry them.