I like Trulock, just ordered another choke for a 20 ga M2 Benelli. I'd recommend a Trulock 'Precision Hunter' extended choke.
For starters, some bores are tighter than others, before you get anywhere near the choke. Shotguns that are 'back-bored' have a larger diameter bore. With this in mind, a choke of a certain constriction would behave slightly different in the tighter bore compared to a more open bore.
Then you would want to factor in the main shot size & type planned. If you read some of the google search patterning articles you should expect a better pattern from a quality after-market choke.
I'd be somewhere short of the fullest of chokes with #4 buck. Another consideration to extend range is to look into some kind of higher quality "T" size shot.
That all said, I have a .680 choke on a Browning Gold & a slightly tighter one on a Benelli M2 for shooting 'T' and #4 buckshot.