You can do a decent DIY job on the boom grip, if you're careful and patient. Part of the trick is to chamfer (if that's the right word) the edge of the grip with a razor blade before you fit it.

Bluechip used to sell the grip and explain how to do the repair. I can't see anything on their site though. You could give them a ring and speak to Brian there (always helpful). http://www.windsurfer.co.uk/diyboardrepairs.htm

As to the Gecko bits, have you tried Boardwise? The tend to be good for old bits.