V6 (or5) holder and the neck counter piece. To fit this you need 1 of M3 bolt long 15 mm and 2 M3 bolts long as per your measurment plus 2 nylock nuts. You also need washers, a 2mm drill bit to drill the main adapter at the corresponding hole in the piece holder, and an M3 tap to tap said hole you made in the Main Holder, just to lock in place the piece adapters there.

To fit the V6, slide ther Main Holder onto the Calibration die holder, lock it with a bolt to the calibration die holder, fit the neck of the V6 (or5) in position such that the tip of the nozzle beary touches the calibration base lip, if it siths on it than adjust the height of the nozzle or the throat in the heatsink till you reach perfection, than place the counterpart over the neck and lock it in position, unscrew the calibration locking bolt, remove the holder and is ready to be placed on your printer.

For the price you have one  V6 (or5) mount and the counterpart to hold the neck fixed.   You need to buy the M3 nuts and bolts.

Word of advice from experience, PLA will fail in time due to proximity of hot elements like heated bed or the hotend, but can print in an open printer frame over 100 hours before it fails sometimes.

If you intend to run your printer on the hot side of polymers do not go for PLA, rather nylon, or PPS or similar, if you intend to go fully enclosed and really hot polymers in printing, I reccomend you go PEI or PEKK.