If you have 17's then use those. Most who get new rims do so because they have the 18's or 19's, or want to protect their rims from any winter damage. 19" snow tires are very expensive, more so than buying a new set of 17" rims and tires to fit those.

 

I got 17's because I didn't want to mess up my 18's. Plus it's a PITA to mount and balance twice a year, and it will cost you ~$60. It's much easier for me to jack up my car then swap the entire wheel.

 

I have ENkie RPM2's for the winter and for the track tires. 17" tires are much less expensive and tire selection is broader. I can change the sets in under an hour and be back on the road. I highly suggest have a complete set for each duty.

 

I got the Dunlop M3s on a set of Kazera 17" wheels and am very satisfied. Since I have the 6 spd my other tires are the summer 18" tires with the stock wheels. I plan on waiting til mid April to put them back on as in NJ we have gotten snow in April and summer tires in snow are flat out dangerous.

 

I put Dunlop M3s in the 18" size on my coup. The stock 19"s are in the shed now. With ASA alloy rims, the package ran $1400 including tax.

Much easier to buy separate rims for the winter tires. Mounting and dismounting the tires for three years will cover the cost of new rims in about 3 winters (mounting and dismounting twice a year is expensive too!). My local car place swapped the wheels for $35, but you can do it yourself too.

So far, the M3s handle well on dry and wet pavement. They do slip if you step on it at the start. No meaningful snow yet -- can't wait to find out!

 

scc - So you're a "believer" now.... aren't ya glad?!

One additional positive trade-off for dedicated winter wheels & tires is you'll be putting less miles on your summer tires, so those will last you longer (obviously it's a bigger investment up front to do so, but it's cheaper than wracking up your car around a pole or into a guide rail ).

Homeslice - I presume you have a sedan? I ended up just getting 16" steel wheels w/ Alpin's and a decent set of hubcaps from www.hubcaps.com and I think in the end it cost me $600-$700 total (including mounting, balancing & install). Plus the shop where I got them mounted includes free swap out of the tires (removing winters & putting summers back on) for the life of the tires. That'll change though after I finally get a hydraulic jack & some jack stands (if I've convinced Santa I've been good ). Here's the caps I got...come on...don't they look like replica mesh rims!?

 

I just bought the Dunlop M3's from tirerack with rims and could not be happier.
They arrived at my door in 3 days, ready to mount. Next day I took a 2 hour drive to Parry Sound, Ontario through a heavy snow storm and they handled the deep snow just great. On the way back, they cut right through 3 inches of slush at 85 mph in the passing lane with no hydro-planing. I was amazed. Normally that would be quite the adrenaline rush.
Next day I drove to Florida and they were very stable.
I found the stock 215's to be quite affected by crosswinds on the highway, so I went with 225's for the M3's. The tires will normally only see snow for maybe 2% of their mileage, so the M3's were a much better choice for me than a full snow tire, like the Blizzacks.