Hey Jeroen.
I don't think my kit and yours are going to be
exactly the same but they are very close. My Yak-1 is also in 1/48 scale. You could probably get some skies for your Yak through an aftermarket company but if not I see no reason why you couldn't build yours with wheels and still do the winter paint scheme.
If you do decide to build yours in the winter scheme here are some tips and advice I was given on mine that would have made it better.
1. Either overspray some of the whitewash on the edges of the decals, or leave some dark camo around the decals. This makes it look more realistic since the whitewash was applied in the field and was in no way perfect.
2. Don't pose your Yak with both wing flaps in the down position.
3. Be sure to put a coat of sealer (flat coat etc.) over the green/black camo before applying the whitewash.
Hope you have success with yours Jeroen!
Hermon