This is a pretty nice Capri, for as old as it is. It would be a nice one to restore.
The only thing the V6 conversion could use, even though it is a stick, is the engine. It would be perfect because it has almost everything neded to make it fit the Alpine. The only thing it is missing, is the oil filter adapter. It already has the rear sump pan, the early timing cover and water pump and all the early pulleys. it would also have the electronic ignition, with all the necessary pig tails for connecting it to your Alpine.
Even though it is a stick, the Capri transmission isn´t very strong and the shifter arm bushings will be worn out too, making it not shift well. The bellhousing will only fit the Capri four speed, so you can´t use it for the T5 transmission.
The price is a bit high unless the engine is strong, then it would be OK.
Jose