Yep that question has been answered 10 times over. It sounds like you have plenty of reading time. For the full run down, just search for all the posts by Cactus and Mack.
There are round and oval bored carbs. 30mm is not 30mm.
I had very good results with an OKO26 (round bore and flat slide). At sealevel and 20C and moderate humidity, I ended up with: main=K102 (stock) + slow jet= K38 (richer) + needle up 1 posn (stock = middle). screw=1+18th. Good unifilter installed. Beware OKO quality control is poor, and these carbs are sensitive to temp and humidity and altitude so ideal jetting will vary. Also beware the round bore carbs can sometimes require better hand throttle control.