pocket door

Got a picture?? On most wooden pocket doors, you can put the contact (3/8") in the frame just under the latch (closer to the floor if you're coming up from there), then put a concealed magnet in the door (abutting the contact).

Piece of cake, friend. About 2" above the floor, drill a 3/8" hole into the door frame, parallel to the floor. Slip just the tip of a 16" long by 1/4" diameter bit into the hole. Drill down to the basement at a 60º angle off the floor and slightly sideways so the drill takes a compound angle. That way if you happen to be above a joist the bit will come out the side instead of having to bore all the way through. Use any press-fit, 3/8" contact. The feeler bit will cut a small notch at the top of the 3/8" hole. After inserting the contact, touch up with colored wood putty.

Basically, you're doing the same thing you might do for a wood-framed slider. Enjoy.

Single door or double door?

single

Then the others have already given you the best advice.

hopefully that pocket door has a secure latching mech. ...the one's I've seen the past 15 years all had crappy locks.

Pocket doors always seem to have so much slop. The interior pocket doors (all I recall seeing actually) usually bounce when you close them. Maybe different construction techniques or preferences are in play up north.

Pocket doors (in Canada) are "sloppy" on purpose. We have to make them that way to make up for the way changing weather conditions affect the Igloo's interior.