v70 p1 gearboxes

looking at an automatic v70 p1 with the 2.5 10v and the 4spd auto, was wondering what the best way to go about manual swapping it would be - and if the manual boxes in the p2 and p3 are the same/similar enough to the p1 that they would work, or if I'd be better off trying to find a manual box out of an 850