For your 9-sp conversion: Shimano SL-R440 shifters & FD-R443 front derailleur. The FD-R443 has a 10t minimum difference, which should match fine with your 52/42/30 cranks.
You
could convert to 10sp: SL-R770 shifters & FD-R773...plus cassette and chain. Just throw this out since you'll be replacing the shifters and FD anyhow. Don't know how the 10sp chain will play with the 6500 crank, though. Definitely the more costly option...and questionably worth it.
Have you looked at Nitto Moustache bars? Interesting looking bar with lots of fans using them for commuting to touring. Plus, you could use your current STI levers as
this person did on his. Or you could use road brake levers with barend or downtube shifters. No need to replace the FD in any case.
Also, look at Nitto's Dirt Drop stem if you want a stem that will favor a more upright position.