Getting ready to file a form 1 on this little bugger. I have a spectre II on the way. Is there any subsonic ammo that'll cycle the action with the suppressor on? Or, can I cut it to about 10" and have bulk box stay subsonic?

If you want bulk box to stay subsonic the barrel needs to be cut to around 4.5".  Regarding subs, it depends on the gun.  My 10/22 will cycle Remington and CCI subs and my friend's will not.  If you are interested in feeding the gun a consistent load of subsonics, an aftermarket bolt handle with a reduced power recoil spring may be the ticket for reliable operation.

I have THIS kit from Kidd and it works well.  It comes with  +10%, standard and -10% recoil springs.

i have a 5.5" non take down model and everything thru it stays subsonic. cycles reliably with all ammo I have tried. gets picky with suppressor off, but when would u ever shoot it unsuppressed!!!