One comment that nobody else has mentioned (although NancyP thought to ask)... While you've said you're mostly interested in capturing flowers, do your interests extend to insects as well? While a 60mm lens and a 120mm lens might both give you 1:1, the 120mm lens will do so from roughly double the subject distance. A flower may not be able to change its location if you point the camera 6" away, but a dragonfly certainly will. Also, if you're going to be shooting alpine flowers, you're going to likely be a) in the open and b) in wind. To that end you should look at some sort of light tent or barrier/ reflector that you can use to tame the wind. OTOH, blurry flowers are pretty too.
Mike.