Synta EQ6 wheight capacity/large OTA's

Hi all, does anybody know the limit of wheight/tube dimensions for a Synta EQ6 mount. I have an 8" f4 Meade OTA but I would like to buy an Orion(UK) 12" f4 OTA to switch with the Meade. Its dimensions are about 14" diameter, 46" long and wheight is only 10 kg. There is also a 14" f4.6 (15 kg, 60" long) and a 12" f5.3 (12 kg, 60" long). I guess I would prefer the 12" f5.3 if it would be stable enough. This is my first Gem and I wouldn't want any accidents...I want to install the setup on a permanent pier for ccd-imaging.Thanks!!

My documentation states 40 lbs, which I presume to be payload, not including counterweights (since mine came with a 34 lb. OTA from Orion).