Can someone recomend a good portable amp, microphone & reverb set up.

When you say "portable" do you mean small enough to take somewhere, or do you mean a small, light battery powered amp that you can carry around to perform on the street?

A light battery powered amp that you can carry around, but to big to put in your pocket.

There are several companies that make small amps that you can clip to your belt, Danelectro and Marshall come to mind. I don't have any experience with these brands, but I have played a guitar through a Roland Micro Cube. Amazing sound coming out of such a small package, and loud!
It is small and light enough to sling over your shoulder, it also has a setting for microphone, so I'm not sure whether you would need an impedance matching transformer or not.
As far as microphones go, the only instrument mic I've used is the Audix fireball V. I like it alot, but if you have the opportunity, try out some others, as They are pricey and you don't want to be stuck with a mic you don't like.