Any cantilever brake will work with road levers.
A "trekking" crank would be ideal, 48/36/26. If you're planning on doing loaded touring a mountain crank would be better, 44/32/22. The Shimano Deore crank is available in either size.
Sheldon Brown said that mountain bike front derailleurs do not index properly with STI shifters.
So use a road front derailleur if you go with STI.
If you go with bar end shifters you can use either a road or mountain front derailleur because the front shifter is friction, not indexed.
I'd go with 9 speed shifters and buy a new cassette. Cassettes are cheap compared to shifters.