The other day my wife was driving my '05 Roadster and while she was waiting in line at a drive-thru the clutch pedal suddenly got very soft (without any accompanying sound or popping sensation) and the release point of the clutch moved up quite a bit. To me, that screams failing (not fully failed yet, the clutch isn't really slipping noticeably) pressure plate and the clutch is also producing that distinctive burning smell, but I don't want to dismiss hydraulic issues either. So I'm trying to decide what all I should order to try to make this a one day job (side note: I am technically inclined, so I have zero qualms whatsoever about the work itself).

1. Clutch kit. I've heard that the Sachs kit is better than the Luk kit, although I've run Luk in my Jeeps and never had problems. Is it worth the extra $$$? Does it, like the Luk kit, include the new slave cylinder with the throwout bearing, or is it just the throwout bearing? JC Whitney has it for $381, which seems too good to be true (Sachs Clutch Kit - JCWhitney) unless I have to purchase the slave cylinder separately (which JCW doesn't list). Also, are there any other higher performance kits that you guys know of that won't totally break the bank (e.g. Centerforce dual friction or Zoom kevlar)? I haven't found any so far...
2. Master cylinder and lines. Just in case there are leaks (I'm going to try to look over them today to make sure, but sometimes those can be hard to spot), has anyone replaced these? How much of a pain are they to get at?
3. Other causes? I can't think of any myself. This is either a leak somewhere in the hydraulic system or a failed pressure plate, more likely the latter, but has anyone seen any other causes for soft pedal and burning smell?

This is really frustrating because while it is an '05, I only drive it on the weekends, and not every weekend at that, so it's got just over 42,000 miles on it. That seems REALLY early for a clutch to wear out! Anything I should inspect that could have caused the premature wear? I'd assume since it's an internal slave design, there's not much if anything in the way of adjustment for the throwout bearing depth and travel... anything else?

And a few procedural questions (there's a fantastic writeup here, but there are a couple of questions I still have after reading it):
1. I have no experience with dual mass flywheels. Can they be turned by a machine shop like a standard flywheel, or should I just scuff it up with 180 grit sandpaper to remove glazing like the article mentions? I've already ordered the special tool to hold the flywheel in place while I unbolt it and I'll be ordering replacement bolts as well.
2. Torque specs - Flywheel, pressure plate, bellhousing, etc. Anyone have them?
3. Probably most important - are there any differences in the procedure for doing the clutch on a Roadster vs. a Coupe? The writeup on here says it's for an '04 Coupe, so I figure my '05 Roadster probably isn't *too* different if at all, but is there anything in particular I should watch out for?
4. What is the range, in sizes, of the external star bits I'll need to have to do this? Any special sizes that don't typically come in tool kits? I've already got some, but I'll go buy whatever else I need if what I have doesn't cover it.

Wow, that was long. Three cheers to anyone that made it all the way through