Shops

i want to make something like that.. I buy a unit from shop and the type of that unit to be removed from shop, so that i can have only one from a kind. i tried "neutral building - remove unit type(from all markets)" but it does work.

Hrmm, couldn't you just look at the Marketplace and see how it memoves items when you buy them? I don't understand the inner working of Shops. Just look at the Marketplace you might find something there.

On the unit sold, set the stock maximum to 1 and the restock rate to 0

its not good. after bought unit death i want to be able to buy another one

It will take simple trigger to do this.
the first one:
Event:
Unit - A unit enters (Playable map area)
Conditions:
(Number of living <unit type> units owned by <Player>) Greater than or Equal to 1
Actions:
Player-Make <Unit type> Unavailable for Training/construction by <Player>

the second one:
Event:
Unit-A unit owened by <player> Dies
Condition:
(Number of living <Unit type> units owned by <player> less than 1)
Actions:
Player-Make <unit type> Available for training/construction by <player>

and there you have it. I tested it so i know it works.

Thank u DarkMage and all of u!