I was thinking of running the 3" extensions until i found the Kuryakyn swing wings for about the same price. Can ride normal while in town and swing them out for a 3" extension while on the hwy.
Haven't ordered mine yet, waiting to build up some more hotel points so i can order some amazon gift cards to pay for them. But is another option for you, btw I am also in the same predicament 5'7" and 29-30" inseam. Going to mock up what 3" would be and try and see if it will fit me, should fit b/c I can rest my heel on the stock pegs and me legs aren't quite stretched out all the way.
Only problem i see for myself with them is they swing out 3" wider as well.