Think about getting rid of the fixed chokes before you do so.
I would consult Carlson, Colonial, Nu-Line, Kolar, and Briley.
These folks can advise if you have enough "meat" in the bbl to put chokes in. I recommend quality service for a fair price than a hurry up job for less monies.
I have seen and heard too many horror stories of folks wanting a fast turn around, and a gun that used to shoot POA/ POI shot off into the next county because the threads were not concentric. I have seen the Choke and / or the end of muzzle end up cracked or downrange because of ill fit, no step below bbl and where choke end threads into bbl, and other fun stuff.
I used Nu-Line back in my day, I mostly had Winchesters I wanted Chokes, and forcing cone work done - Nu-Line is/ was where one obtained Winchester parts and such.
I know others have used and recommend the others...I forget whom Lee uses, I believe kudu uses Kolar.
Get some input from the aforementioned companies, see what their experience is on that bbl, prices, options of chokes ( external knurled, steel shot approved, increments in 5 thousandths...etc.)
For instance one of my Win bbls is .738 [IIRC] I have the Nu-Lines and for skeet I used a external knurled choked that is .735, meaning I only had 3 thousandths constricton. My Forcing was good, Nu-Line's expereince with that bbl, suggested with the screw chokes to take a tad more step out of the FC. Hey I listened, and said do it. All the other Work I and others had done was first rate. All my Nu-Lines are external knurled, increments of 5 thousandths, and are steel shot rated.
There is hardly anything some man cannot make cheaper and sell for less, those whom shop for price alone are this man's prey. -John Ruskin