If you send it out, either A2, or 01. Both come as spheroidized anealled. Dead soft. You can cut slivers from either with a pocket knife. Both have a vast range of sizes to choose from, with 01 having the most.
If you are going to do stock removal and send the blades out for heat treatment you might want to consider sticking with air quenching steels like A2 or D2. A lot of the professional heat treaters only do air quenching steels, though if you look hard enough you may find someone who will handle oil quenching steels.
If you are sending it out you can start with just about any steel you want. There's not gonna be a whole lot of noticable difference for someone just starting between any of the common steels, as long as they're annealed. Probably want to avoid the "super steels", though ( those with high vanadium content, to be more precise). I think Peter's will heat treat air hardening and oil hardening steels. O-1 makes about as good of a blade as you can ask for if stain resistence isn't an issue.