I've looked for links to the info you're interested in for many many hours, and was able to get enough hints to put everything together. Here's a brief summary of where I'm at, based on memory(don't have time to look everything up right now).
I though I was going crazy for a while because the site search was very erratic, one night a thread would come right up, and the next night, only posts from 2008 and back would show up. I told my wife that I have to search every topic every day because it changes constantly. It seems like the issue is fixed because my searches are much more productive now????
Motor Controller:
Sources: ebay?, a couple of guys on here, still basically searching
There is no step by step for controller mod thread that I have been able to find. I used to repair car audio equipment and motor controllers are very similar in construction to amplifiers so figuring out the controller mods was almost more common sense that learned on here. It's interesting to see the differences in fets used. The IRFB3077 seems better for applications using 36-50Volts because of its lower RDS-on(current required to switch) while the IRFB4110 is better for 60V+ applications. It's all about increasing the amperage capacity and then reconfiguring the controller to tolerate the higher volts/amps. This is done by messing with the value of the shunt resistor(one member mentioned half value) and with programming. The circuit traces on the board need to be beefed up. This can be done by laying a pool of fresh solder on the traces, cutting a stranded wire to length, tinning it, laying it over the trace, and flowing solder over it. You have to be careful that you don't overheat the other components on the board while doing this. They can be removed, or cooled externally(pieces of heat sink clamped to them, air cooled, etc). I have also noticed that manufacturers and modders alike are putting ceramic resistors right down close to the board. They will transfer their heat to the board and weaken solder joints over time. This is one of the differences between a controller that lasts ten years instead of two though. If you've ever had a ford truck with a cd/tape player that has a burnt out display, the resistors being too close to the board are the cause. I never put a resistor that heats up closer that 1/2" to the board. Also, quality fets and caps help a lot. Ratings don't mean to much these days. Digikey is a great source for components. Also a good source for hall effect sensors for the motor.
Motors:
Astro3210, 3220, etc.
Turnigy,HXT, etc
Source: just search online, easy
On the cheaper motors, it's a good idea to take them apart, make sure the magnets are in stout, re-glue with high temp expoxy if necessary, replace the bearings(many sources, just search miniature bearings), and make sure windings are tight and secured. It has also been recommended that the big turnigy's be rewound/reconnected from delta configuration to wye. This increases the torque that the motor puts out and lowers the rpm, allowing for less reduction in your transmission. BLDC Motor winding configurations can be searched online for more details. The hall effect sensors need to be mounted in the correct position in relation to the magnetic fields produces by the motor. One of the members here did some gauss testing and if I remember right, the optimal placement was 5-8 mm above the outrunner can and away from the edges, towards the middle. There have also been a few different strategies posted about the radial positioning of the sensors. You'll just have to search this stuff. I seem to remember, a 120 degree even spacing(which makes the most sense to me, and something like 17.34 degrees. I definitely see how the 17 degree one would work, but it seems like the 120 spacing would "spread the load" out on the different coils, and potentially make the motor run a little smoother. It seems like putting the spacing at 17 degrees would make the controller "throw the motor around" with three nearby coils every time??? I don't know, I haven't had time to get into this area yet as I'm still ordering parts. I found an awesome PDF somewhere that is a must read.
Transmissions:
Sources:banebots, matex, stanton, neutgart, recumpence drive
This is wide open territory. Recumpence's drive is beautiful, and does the job very well. I like the gates powergrip2 belts for the first stage. This is an area where, if you can't design something yourself, you're best off getting a drive from recumpence. He's pretty much nailed it. I've been researching this for four years and came up with a very similar design. I've looked in to every alternative, and dollar for dollar, you can't beat it.
So there it is. I hope it helped a little. It helped me just typing it all out.
