I've seen good slide played on most guitars....and it must be said with most gauges of string. However to give yourself a sporting chance. You want the heaviest Martins. Bronze. A brass john dunlop slide. They will engage to gether nicely. get it set up by someone who knows about guitars - like someone who makes them. he will know about any adjustments.

look for a good tutor , or if you can't find one. Ask for Michael messerd cd on the subject, and scott ainslie's video on Robert Johson.

If you are in the UK go to one of Kevin Browns One Day Slide Schools in Bath. they are held twice yearly.. ask questions of anybody who sounds alright, try and analyse their sound. look at their gear and work why they sound like they do.

Have fun!

all the best

Big Al

Sit down and work on your touch. its all about