slider or pin type for 11 inch rotors? 69 b bodyfor factory calipers,which would better or both about the same. thanks

Hopefully member hemi71x sees this or send him a PM. He is more well informed on this since he does brakes (there are more too). I think they're pin type.

factory calipers were pin type. The sliders will fit but are for newer calipers

Neither. A '69 B body had fixed calipers.

If you already have BENDIX, 4 piston caliper, disc brakes, on your 69 B body, NOTHING else works on that system.
You change over the entire brake system, either pin type, or slider type, onto your car, single piston calipers.
Use whatever style brake system becomes available to you, for the swap.
Both systems are going to "brake" your car, and it's no problem in getting pads, calipers, parts, for either system.

I think he means "brake" your car. Isn't it amazing what the potential impact can be from a simple spelling mistake.

When the time comes get some Ceramic pads & a bed in procedure is time consuming but very beneficial. EDIT they may want a coarser finish (have your lathe operator set a faster speed) or vice versa for ideal performance. More friction (rougher) is more braking (& faster wear) but see what the pad MFR says