The tekno driveshafts are on sale right now on amazon, you can get them from tekno directly but its a bit more.
If you use the vxl3s make sure to add fans to both esc and motor but mostly the esc, if you gear properly you shouldnt have any issues. For fans reccomend the amazon aluminum ones (search for 30mm rc car fan and a ton of them show up) theyre relatively cheap compared to protek ones and are equally as good, if you want to go cheaper the yeah racing 30mm ones are also good. For motor mounts i use the exotek one for 1/10 scale not 1/8 and its low profile and easy to mount just need a bit a locktite.