I think Acera would do fine for touring unless you carry TONS of weight. I have used them for mountain biking and they perform well... a bit on the heavy side but who cares? Regular lubrication in a must but if you are a good mechanic that wont be much of a hassle and you will be saving lots of bucks compared to the LX/XT/XTR stuff.
Alivio also works nicely. It is aimed to recreational/entry level mountain bikers and should work well in touring applications.
Ricardo