surface mount (sorta-acoustic) sliding doors.

Hello all second post here. I'm just over a year into construction of a freestanding home studio in austin, texas. Briefly, (but for the sake of semi-full disclosure..) It's a cinderblock structure with a hollowcore concrete plank roof. (there's a second floor which includes a roof deck and a screen porch and my wife's painting studio, only accessible by a freestanding exterior stairway..) The foundation wall (which supports the block walls) surrounds a floating slab which supports the interior frame wall and ceiling. I've had consultations from a couple of studio designers and an acoustician on the room dimensions, and they look good. (maybe they'll SOUND good, too....) My entry and exit rooms to the studio building are also my big and small iso rooms, so my exterior doors will be weak links to the great outdoors, which includes an apartment complex that is cozily close to my back studio door. (about 10 feet...) These iso rooms do not have enough space for a seperate swinging door to the interior, and I am wondering if anyone has had any luck or experience with surface mounted doors as a second leaf in a (semi-) acoustic doorway assembly. I'll do as good a job as I can with my exterior doors (they swing to the outside, the jambs are welded and fully mortared, and I'll probably replace the foam filled metal commercial doors which I have now with solid wood doors, and do as much gasketing and weather stripping as I can, and decide on either cam lift hinges or a drop seal bottom..) I've seen residential surface mounted door assemblies, but they are by nature rather "leaky". I'm wondering if there is a method of assembly or a style of surface mounted door (To mount on the inside of my frame wall) which will help me partially plug my big weak link, for the sake of neighborliness..... Even if it just gives me a handful more db of help.. Oh, and thanks for this great resource. This website has been a huge help to me. Brian ps, I've got a mac, so I can't easily give you drawings, so I'll keep trying to draw with my words. PROST!!!