Reverb/Delay pedal

Delay depends on whether you want analog or digital.

Try a Line 6 Echo Park.
Not that cheap and they weigh more than most singular pedals, but sounds good and very versatile and offer everything from vintagey analog delays to ultra long, clean digital delays.
Check out their Verbzilla pedal too for a good reverb pedal.

If not, perhaps the well known Boss Digital Delay would serve you well and can be easily found on the used market, if nowhere near as versatile as the Line 6 pedal, but obviously cheaper though.