Stock engine -- no modifications.
Forgive me if you know this already and please disregard if you do.
There will be some loss of lower end torque and throttle response with the larger carbs unless the engine is modded to match. If mods are part of your plan I'd like to suggest waiting till then to jump carb sizes carbs by any more than a couple few mm's.
Your original post mentions not wanting to rebuild the current carb.
FWIW 30mm was the most popular venturi diameter on the forum for modded bikes during the Iron Barrels hey day here. The best example I know of is the Harris Scrambler with the AVL engine. Free flow air filter and exhaust, 8.5 to 1 compression ratio and Redditch S cams.
I'd like to suggest hanging onto your lower half torque and throttle response by not going bigger than 32mm. If it were me, 30.