In reply to PPP:
Getting around in Aviemore without a car shouldn't be too hard, I'm sure you could hitch a lift up the ski centre road relatively easily and if not i'm pretty sure there's a bus service going up to the ski centre as well. From the ski centre you've got loads of options of where to climb/walk. Sneachda is good for the grades you mention despite being the winter climbing equivalent of McDonalds in terms of accessibility (45 min walk in, and fairly safe bet for getting something in condition). You can also venture over to Loch A'an side if you're wanting something a bit quieter. There's easier stuff on Hell's Lum and Stag Rocks although be careful its not too sunny (yes its a problem in winter sometimes) as both crags catch sun.
Might be worth having a look at Torridon as well, the youth hostel there often has other walkers/climbers staying and it's a pretty special place in winter.
Good luck!