I like Competition Clutch and SPEC, personally. I had an Excedy clutch for a while, that blew huge donkey dicks. Rough engagement, loud chatter, heavy pedal....etc. I'm sure some Excedy clutches are great, I just don't know which ones those are.
I don't know much about Clutchmasters but I know a lot of people like the Stage II from South Bend.
Btw...if you are already seeing a bit of slippage, try to baby it, keep it out of boost if possible until you decide on a new clutch or your going to be stranded. Once a clutch gets bad enough, it quickly becomes undrivable.
Are you planning a build in the future? Might the car see any track time or agressive driving?
With more power and abuse, you may quickly wear out a Stage II. If you choose wisely, you could get a Stage III or IV that would be comfortable to drive and also support more power in the future without having to buy yet another clutch.
In the meantime, check out the member journals on the forum and see what clutch people are running with what mods/power levels.