Your right - the Small Clone is the Chorus, I get those mixed up.
These are apparently the effects Pat Metheny uses;
"Roland Gr-300" guitar synth, "Digitech 2101 GSP Guitar Pre amp" and the "Lexicon Prime-Time Digital Delay"
For Chorus, he uses two Lexicons simultaniously, with different delay times to create a natural reverb effect. surprisingly, it's actually similar to what U2's The Edge does, just with much shorter delay times.
"The output of the Digitech, just like the Acoustic 134 (his amp), is connected to 2 Lexicon digital delays, one on his left at 14 Ms and one on his right at 26 Ms. Each delay has a slight pitch bend controlled by a VCO (sine wave), what makes his guitar sound chorused. It's this 'natural' chorus that Pat is after since he doesn't like chorus coming out of a box." (www.jazzguitar.be
I think you could get a desirable tone with almost any of the pedals people have suggested on this thread. But, to try and really nail Pat Metheny's tone try using two Delay pedals with the delay times from above. (14 and 16 ms) The closest combination for simulating Pat's sound (short of getting the two Lexicons) might actually be a Chorus pedal (for the short delay/detuning effect) and a delay pedal set at 26ms. Anyway, just some more suggestions to play around with....