HB, it really shouldn't be too big of a problem. 60 degrees isn't all that far off from 65. You'll probably slow down aging some which to some would be a good thing. Also, if you decide you just have to go higher, there are thermostats you can buy to make the temp go higher. Do a search on Wine Coolers and you'll find a few mentioned in different threads. You will definately need more beads, if I'm right without looking at the actual link and you are looking at a 42 bottle cooler. Find out the inner dimensions and go over to Heartfelt's website or check the faq at the top of this page. My guess is you might need close to 3 lbs for something that size? Mine is a 32 and 2lbs is just about right.
Considering your temps you may be able to unplug your cooler in the winter. No way to tell until you have it during the winter and can try it out, but my guess is it'll hold below 70 degrees in the winter just fine. Of course, you may not want your temps swinging around at all if you are doing long, long term storage.
Others will have some more indepth info for you I'm sure, but there's my .03.
Oh yeah, and rock steady at 63% on the second shelf for the second day in a row. top shelf looks to be about 60-61%. I'm guessing it goes from 60% up top to somewhere around 67-68% on the bottom. Hopefully it'll stay solid and my worries will be over. I've got cigars in boxes on the top shelf, my tray on the second shelf and my NC's down towards the bottom.