Just as with recumbent bikes, there are trike models with low reclined seats and there are less reclined higher ones. Some Anthrotech tadpole trikes have relatively upright seats, most delta trikes are higher and more upright than tadpole models. New trikes are expensive, but used ones can be relative bargains if you keep your eyes open in the usual places and can travel. They might all look similar but when you look into it, there's more difference between them than just seat height and wheel size or configuration.
Although there's a lot of hard won expertise on CC, you would benefit from advice from such as Kevin at DTek as advised further up thread. Finding the right trike could save a lot of trial and error and at the least add fun to your mobility, at best kindle a new enthusiasm for cycling as discovering recumbent bikes did for me several several years ago. It is one of those things that if you don't try it, you will never know.