I'm building a minimalist 20 ga single barrel. I have an old Magtech 20 with a modified fixed choke. Im going to have a gunsmith ream and tap it for browning invector chokes. I don't want a super tight pattern. Just a good even pattern at 40. I will be shooting LB ##6 and TSS #9. 1 5/8 oz loads. what choke do you recommend??