I have a sabatti dr in 450. I have a trijion sight that I want to mount on it. Can any one tell me what picatiny base I need to buy?

The base that comes with the rifle is a Picatinny base, which is just an ARDEC rip off of the original Weaver system.

A standard weaver base came with mine not a picatany. And the screw holes do not match up

The Picatinny base is just a Weaver base with more slots in it; so just mill in the slots where you need them for your scope mounts. As for your holes not matching; how far off are they? Otherwise, you will have to make a base anyway. No one makes a base for that rifle because they came with one. Brownells sells blank Weaver base stock that you have to mill the slots into. I have had 3 Sabattis and all the bases fit.
I can make one or makes yours work if you send me the base and the scope.