Based on what I have read, if I were in your position, I would get the SRM-323s. Accoding the Spritzer the little amp 252s is very good and cheap but I believe it has a wall wart which might bother you.
If you are interested in buying one new, Justin/Headamp sells them cheaper than Elusive Disk (same price as Yama) and ships fast.
http://www.headamp.com/order/index.htm