To the original poster - another angle is to keep your Martin for other stuff and find a cheap-but-decent alternative guitar for the jazz gigs. If you set yourself a limit of (say) 500 pounds - which is probably only around twice the price of a good aftermarket pickup - and play what is around in the shops you might find something that sounds great/just right amplified even if acoustically it is not your Martin. We (my wife and I) have 6 nice acoustics between us, and one that sounds great amplified - though not the best acoustically - is a little Tanglewood which cost about that. It has a built in B-band pickup system, sounds like a million dollars! That way your "best" guitar also does not have to travel to e.g. outdoor gigs in inclement weather, get blown off stands by the wind, etc. etc. Just a thought - plus you can audition them with the pickup already fitted before committing yourself, a hard thing to do with your own "best" guitar. Cheers - Tony