Yo Man of Soup: [Minastroni or Chicken Noodle?]
Your reverb on your amp is probably a fixed reverb; can't model it or program it and you only have one or two choices.
You need a reverb box and there are many out there within a reasonable price range. Then, you can choose from many reverb rooms and edit any of those rooms to suit your ears.
I have an Ensonique DP-4 reverb box which has a zillion different things on it but one patch is called Nasty Harmony and it can create some interesting effects, as well as its alter-ego patch called, Sweet Harmony.
You will have to invest some $$$ if you want to get some "good stuff" down on tape or disc .
Welcome to the world of constant learning,
Green Hornet