Tony - I got my bellhousing, flywheel, clutch, and new Tremic TKO 500 from American Powertrain. They will also send me the new driveshaft once I am ready with the measurements. It was a package deal - instructions, bolts, wiring, etc. Walt at Vintage Jag Works can also supply the parts needed - as you have discovered. I am not much of a fabricator or inventive enough to think I can do the install without serious guidance. You can save money for sure - but I really needed the backstop.
With regard to the clutch fluid reservoir - yes it needs to go high. Which will be hard to do. Ideally it should be above the master cylinder. If you can not do that, you can mount it lower, but you will likely need to lift it higher than the clutch master cylinder - like an IV bag - to do the initial bleed for the slave cylinder - in my case a HYDRAMAX clutch release setup.
Good luck - happy to help where I can.
1984 (Euro Spec) Vanden Plas V12