Make sure what ever you do that the cup liners you choose are stainless the plastic liners I have heard caution about the plastic esters coming out of the plastic when subject to hot liquid & you don't want to ingest the esters because they are bad for you. The plastic lid isn't quite so bad because the hot liquid isn't in contact with it all the time. Same thing goes for microwaving food in plastic use glass or something like Corningware.
Also I don't know about the rest of you but I like the wide bottomed narrow topped mugs for travel. Would a wood like teak & wiping it down with an oil be a better choice than some other finish? Also is there some way to make the liners removable for washing?
"Forget the flat stuff slap something on the spinny thing and lets go, we're burning daylight" Bart Leetch
"If it ain't round you may be a knuckle dragger""Turners drag their nuckles too, they just do it at a higher RPM"Bart