A pretty std touring/drop bar build is Tiagra 9spd STI levers and front mech (MTB mech doesnt work). Deore or similar rear mech. 9-speed cassette 11-34 on LX hubs. MTB chainset and Tektro 520 brakes.
This is far from ideal:
The STI gear cable interferes with most decent bar bags and limits the positioning of the levers.
9 speed generally sucks for touring, it requires to much care and feeding, it is always going out of whack. The front mech trim feature is very hard to use.
The affordable large ratio cassettes (11-34) have a lot of flex in the 34 ring so setting the end stop of the rear mech is tricky. The expensive XTR cassettes are stiff enough to work well.

Bar-end shifters simplify the matter and provide better redundancy.
Butterfly style trekking bars enable you to use the whole MTB system with V-brakes.