I recently purchased a 2001 M750 with 10,000 miles and with a slipping clutch so I can give you some decent advice. Recognize my bike had 10,000 miles and unknown oil and yours has 30k+ miles.
First, if you go with the Barnett RQ clutch kit, you will get steel and fiber discs, springs and spring collars. Cost is right about $165. The engine case cover does not require a gasket, but one is available through the aftermarket for about $15.00. If you wish, just use a very thin coating of permatex instead of the aftermarket paper gasket and all will be fine for leaks.
Now, about the Barnett clutch kit. After installation on my bike and after about 400 miles of use, the Barnett clutch was impossible to find neutral from 1 or from 2. It sucked. I thought after some miles it would get better, but at 400 miles it was almost the same as with 0 miles on the clutch. The bike shifted very stiff and personally, I hated it to the point it ruined any desire to ride the bike. I pulled the Barnett clutch, called Barnett and got them to take the used clutch back minus the springs. I kept the Barnett springs which are a tad stiffer than the stock DP springs.
I reinstalled the stock DP clutch disc and fibers after scuffing up the steel discs and briefly soaking the fibers in gas to remove any oils. This was done b/c I did not know what oil was used in the bike which may have contributed to the clutch slipping. The fiber discs were allowed to dry and then were reoiled and then the entire clutch reinstalled using DP steel discs, DP fibers, DP collars and Barnett springs. All was great, no slipping, easy neutral finding, etc. Life is good.
Personally, I do not recommend the Barnett RQ kit for the bike. I would however recommend the Barnet springs. You want the MT90-6C spring kit which uses springs rated at 43.6 lbs at 1 inch compressed. Get some new DP steel discs, new fibers and reuse the stock spring collars. You will pay a bit more for the DP steel and fiber discs, but if you ask me, it will be worth it. I wont use Barnett discs in my bikes again...I had the same problem with a Yamaha RZ350 with a Barnnett clutch.
The entire project of removal and installation is straight forward and should take no longer than 1.5 hrs for even a slow person.