Hey Tim,
Perhaps why noone is answering is because the list is quite extensive. It depends on what your rebuild will require and also depends on what level of tuning you want to do when it is time to rebuild. It's a difficult one to guess but that said, there's no problems with buying some of the items now.
I'd avoid buying things like pistons, rings, bearings simply because you won't know how badly worn down your crank will be and how much grinding it will need. And same goes for the pistons and rings, will going to 1310 be enough? do you want more cc's? How bad are the valves now? will you need new valves or just regrind the seats? If you buy Maniflo medium bore LCB extractors, will this be optimum for the build that you want in the end?
There will certainly be some parts that you will buy and not use because it's not needed or it's the wrong type/shape/size/style/tune for your build.
Then comes the performance questions... standard hypatech pistons? Forged pieces in case you want to turbo? or something special like GR's pistons? Rimflo vlaves? double valve springs? 1.5 or 1.3 rockers?
That's just the top end. Gearbox is another can of worms. But a good start for gearbox is a std gearbox rebuild kit from minispares. I got one of those and was not disapointed.
If you are doing most of the work yourself you can get away with it all for around $1000 - $1500 in parts depending on how bad the 1293 is right now, so it's not a huge investment (for a car!! lets be serious!) so maybe that's not too many sleeps on the couch
