Mytyres.co.uk do sets of winter tyres on steel wheels, you just need to enter your registration number and they will come up with the recommended wheel and tyre combination with prices. Alternatively, check the car handbook and type in the size yourself. You need to do a sense check on the recommendation, for instance it used to recommend 15" wheels for my car, but they won't fit over the brakes! But it gives you a starting point.

As other posters have stated, many european tyre e-tailers sell wheels and tyres ready to put on the car when the weather changes (yes there are several I know about, French & German).

Last year I purchased winter tyres and had my local tyre specialist fit them to the existing alloys (old tyres were worn so discarded), in March I purchased 4 summer tyres and put the winter tyres in storage. Last week I purchased a set of original alloys for my car, and will mount the winter tyres in the autumn when it is time to change over. I sourced the alloys on ebay, a breakers yard was selling them at a good price.

If looking for steel wheels I suggest contacting your dealer to see what price they will offer for a set of 4, get the part number and search the web too. Some dealers are set up to supply winter tyres & wheels, it depends.

depending on where in the uk you are we can help

however if you are not located near us, your local tyre depot/ arage should be able to help,
some companies have stared doing good deals for vredestein (extremely good winter tyre)
I think even costco do them as well