Are there any inexpensive 35mm compacts or rangefinders (new or old) that have angle finders made for them or that can be adapted to them?
By "angle finder" I presume you mean a waist level finder which can be
viewed at a distance from the eye. But, there is also such a thing as a "right
angle finder" used with SLRs which must be put to the eye for use.
There are certainly lots of SLRs and TLRs with waist level finders or right
angle finder attachments but for compacts or rangefinders? That's a tough
one.
If you want a WLF type finder you could possibly adapt one of those simple
WLFs found on many Kodak folders by attaching it to a flash shoe and
mounting that to a RF camera. Or, make one with a small mirror. It would
be crude and you'd have to practice with it to get the framing right, I
suppose, and you couldn't use it focus obviously.
Any particular reason you don't want to use an SLR?