I had some years ago.  With a manual transmission  it should be easier
to have any of them maintain speed, even the simple ones that run off
engine rpm.  With an automatic transmission you have to have a real
speed signal due to slip in the torque converter.  Although with
today's lock up converters it might not be as much of a problem.   To
make installation easy you'll want one that has a long cable from the
servo so that you don't have to try and shoehorn it in right by the
throttle body.

Having done this twice before I would not bother installing one again,
I just didn't get enough use out of it to be worth all the trouble of
installing it.  YMMV