ABS module problems PLEASE HELP

So I am having a ridiculous amount of problems I have a 2006 Nissan Titan The ABS SLIP and BRAKE light are going crazy along with my speedometer is going wacko which is causing my transmission to act up out of 2nd gear So took it to a shop they gave it a look , hooked it up to the diagnostic and they're saying it is the ABS module For sures but they can't find any refurbished ones and Nissan is completely out of them I don't know how true all that isBut I'm looking to see if just maybe they're wrong and if anybody knows anything of how I can solve this problem I'm out of solutions, PLEASE PLEASE ADVISE