If you want to use the 914's transmission (much easier than converting a 915 tranny!), you'll need the "adaptor" flywheel that bolts to a 3.0+ motor and which also fits in the 901 bellhousing. If you're keeping the DME (tougher to do than swapping on carbs, but better IMHO) then you'll need a flywheel with provisions for the crank position sensor. I think we can get those.
There are other sources for the parts, but for obvious reasons I won't mention them...
I will say one thing, though. There is a very inexpensive source for "complete -6 conversion kits". And from what I have read in a few places, you get what you pay for from them. There have been enough complaints about their customer service that I would think several times about using their stuff, even if I didn't work for Pelican.
--DD