Well.. any effects purchase is really personal preference and what kinda style and tone you are expecting to get from it. Me personally... I would be adding a chorus effect to my selection, if I already had what you have.. especially so, since you mention that the reverb on your amp is not so great.

I feel that a chorus effect, when it's on a slow rate, about 3 or 4 out of 10 when looking at the knobs on the effect pedal, and about 2 or 3 out of 10 for the effect/depth knob.. it gives a really open/spacious/roomy feel to the overall tone.

I personally wouldn't bother with compressors unless you are recording or performing live.. or when it is the style/tone that you need a compressor for.

...but then again... I am no effects guru.. and all of this is just what I would do.. my opinion... rather than potentially good advice.. hopefully someone else with more effects knowledge can shed some light on this thread.