The problem is not that those methods won't work, but that you won't be there to gauge what they need, and won't learn how to water properly. Such methods are used when people have to go on holiday for a week or two, and certainly if you're 'field growing' trees (planted in the ground, or in very large training boxes), but so much of the understanding of your bonsai comes from observation of each tree just about every day (you're not planning to go from no trees to 60 overnight are you?), and while you may feel you're just going 'to water' each day, you are also checking for other problems, cleaning up dead leaves, learning how each reacts to watering that season, whether more light's needed, etc., and if you don't even have time to water, maybe bonsai isn't for you.

Most of the time I will be able to care for the trees on a daily basis. What I am asking abut is the feasibility of keeping the trees healthy when I am out of town for a few days to a week or more. Can someone give me specific advice as to what works best-wicking, driplines on a timer,etc. Also, please recommend where such devices can be purchased. Thanks

Ramsay,
I know some people on the Hoya forum that use a wicking system. If you get no responses here you can try posting there. Or you can post on the African Violet forum (if there is one).
Good luck,
Gabi

Try www.bonsaihunk.us/cultural.html, and particularly www.forum.bonsaitalk.com (lots of very experienced people there) for more answers.