Since you're in the area, can I suggest visiting Shinwa International in Fremont?
They will almost certainly have at least one sitting on the floor that you could measure, especially if you sweet-talked them a little bit about how you might buy it...
Note that the engines come in two basic flavours, known as the 6-bolt and 7-bolt. For most applications, the 6-bolt motor is preferred. If the flywheel is visible, count the bolts. If not, consult
http://www.vfaq.com/mods/early-late-engine.html for the obvious external signs.
Later-model 7-bolt motors have the torque mounts attached to the transaxle, wheras 6-bolt motors and early 7-bolts have them attached to the block. The later-model transaxles will mate with the early-model engines, so you can mix and match a bit to get these mounts in the right locations.
Good luck with your swap. It may encourage you to know that we've seen pictures of a 4g63 swapped into a Porsche 911, so it's know to go some... odd places.