If you want to check the current length of pull measure from the center of the trigger to the center of the pad.
I did some quick googling, and it looks like the older axis had a 14" lop, and the newer 13.5.
Personally 14" is about perfect for me, at 6'2 and average build.
Ive found that with stocks that have a vertical grip, my personal preference is to run a slightly shorter length of pull than it is with a open gripped stock. This is just my personal preference.
Since you dont know what your preferred lop is, and i assume your not having them fit a recoil pad, id suggest going with the stock lop to start with. If that feels too short id just buy a cheap 1" or so pad from ebay and fit that. If you go with the ProV there isnt any taper at the heal or toe so you can fit a pad to it easily with pretty much any bench mounted sander.
The flip side is you could order long (@ 6'6, qnd if your arms are long you may prefer a 14.25-14.5" lop) and cut it down till it fits just the way you want. I dislike cutting stock, and know where i like my lops, so i usually go the other way.