Not sure if this is what you mean but the Ransom Rest is the 'gold' standard for mechanical pistol shooting devices.
It's expensive and you need inserts for your gun to fit your gun onto the rest. Ransom has a *large* number of inserts for different guns.
To me, the Ransom Rest is something a shooting club should buy to be used by the club members as IMhO it's too expensive for an individual. How often as an individual would you use it anyway?
Most of my friends use a sandbag or bag of rice on a table to give them a pretty good supported shooting position.
Ransom Rest page:
http://www.ransomrest.com/
Ransom Rest for sale by Midway:
http://www.midwayusa.com/product/252...-shooting-rest
Ransom Rest handgun inserts:
http://www.ransomrest.com/inserts.html