Go with the 22 ,that way , if you want you can have the barrel cut crowned and threaded , this option gives you the most choices later on . First off you can chose how long or short you would like it to be , second and in my opinion the most important is you get a " target grade crown " , third you get it threaded so all the cool ar -15 flash hiders and muzzle breaks will simply screw on the end , because they have the wrong threads in its stock form .
I found this later on ,
The Advantages of Cutting, Crowning and Threading Your M14 Barrel
When you CCT (cut, crown and thread) your M14 barrel, you can incidentally obtain a target grade recessed crown on the M14 barrel. Also, if the threads are cut properly, the LMB is aligned precisely with the bore not with the outside of the barrel. This re-crowning may improve accuracy but it will also improve the rifle's balance and the rifle's swing weight at the muzzle: three desirable characteristics in a modern rifle system.
Furthermore, with a threaded barrel, slight rotation of the LMB offset left or right, adjusts and optimizes the compensator to the ammunition and shooting style of the user. You can effectively fine tune the compensator to push the rifle in the correct direction for tighter double taps. Left handed shooters take note.
For owners of M14 rifles with out of index barrels, the CCT and installation of the LMB+FSB will effectively correct sight alignment at the muzzle. There is no need to re-index the barrel.
The M14.ca LMB also offers a stronger muzzle device to barrel connection than the original M14 muzzle device it replaces and affords the ability to conveniently switch out future muzzle devices with simple tools.
The M14.ca LMB and FSB set offers secure, effective muzzle control and a solid platform for a self-illuminating front sight, or otherwise. Please review our Product Data Sheet for a list of shipping components (listed below).