Hi,
Never fished the Seychelles but would advise taking some fly fishing gear. Its got bonefish, milkfish, trevally fishing on fly etc, though if ya hook a big un your gonna need a lot of backing :wink:
Guided fishing will probably cost quite a bit, though if you could get a guide for one day just to get an idea it would help.
Game fishing on some of the boats for sailfish, wahoo, bonito, tuna etc should be possible.
Anyway here's a couple of sites i had in my favourites for seychelles:
http://www.seychelles-flyfishing.com/
http://www.seyfly.sc/welcome/welcome.htm
If you do a search on google you will probably find a lot of info.
If you get among the fish you should have fun :D
Ryan