This is probably not going to be a popular answer, but you might try looking
for an Arion SAD-1 Stereo Analog Delay. They don't make them anymore, but
they're not too hard to find, and they're cheap. And like the name, it's
stereo. It sounds really good, nice and warm, very natural. Doesn't do the
feedback thing like a Boss DM-2 or Ibanez AD-9 (both classic analog delays),
but I don't need that sound.
For echo and slapback, a very inexpensive guy is the soundtank delay by
ibanez, one of the few decent-sounding soundtanks.