Watch out for issues when running that DOT5 fluid. It's not compatible with DOT4 and can corrode and damage components when mixed. Usually the seals need to be replaced whenever switching to DOT5 in order to eliminate any chance of the fluids mixing.
I've read that some newer brands of DOT5 play nicer with the DOT4 fluids but, just be on the lookout for potential problems with that.
Edit: Looks like that's already been covered, sorry.
If you can find DOT5.1 go for it but, your bike was designed to and can run perfectly well with DOT4. DOT5 isn't all that great, it has a lot of shortcomings. It's main use is very high heat racing situations where glycol based fluids just can't stand up. But, for example, they tend to be so 'spongy' and tend to trap air so badly that they cannot be used in most ABS systems, they can damage valves and they create such an unpredictable 'flow' that the ABS system won't work right. Now I know you're using it in a clutch but, you get the idea. It's not 'better' by any means, it just handles more heat, but your bike doesn't produce enough heat to boil DOT4 so you don't have a need for DOT5, and I would venture a guess it would have some unintended consequences with the clutch as well.
If for some reason you feel you need to go with DOT5, be aware that it'll take more than an alcohol flush. You'll need to replace any seals or other rubber parts (save for maybe hoses) as they can absorb the old fluid, introducing the reaction down the road. You'll probably want to consider doing that anyway, I'm afraid, as whatever you introduce now will react with incompatible fluid soaked into the seals, so you're going to be chasing leaks and damaged components until you get it all out.
"8 But God demonstrates his own love for us in this: While we were still sinners, Christ died for us."
Romans 5:8 (NIV)
2006 Vulcan 900 Classic LT "Couch-a-Saki/Mini-Bagger"
2011 Honda Shadow Aero 750 (Wife's)
Last edited by Romans5.8; 10-09-2012 at 12:51 AM.