Singlespeed & Fixed Gear - Building a winter fixie... What frame should i fix?

its snowing outside. i guess its time to put together my winter commuter. i have plenty of bits to make it happen and im going to try to do it tonight... i have three frames to choose from: a walmart royce union mountain bike (heavy), an 80's centurion accordo, and a vintage schwinn speedster. ive already decided against the speedster... What would be the ideal frame to fix between the mountain bike frame and the accordo road frame? of course i favor the lugged centurion but i wasnt sure that road geometry would be ideal for winter/ice/snow riding. is mtb a better choice for fixed winter riding?

its going to be a loctite fixie.

I just threw together an old steel Stumpjumper (rigid) but I have it set up with a surly single speed. I'll try it out like this and make it a fixed when I can buy a cog and lockring.

actually, i just brought the royce union up from the shed. i thought those wide tires would fit on an old frame, was wrong of course. so now the question is whether i want to got to a shop and buy some 26" tires that will fit the accordo or just convert the royce union and ride.

this is going to be my first full winter of commuting so i dont know what to expect of riding in icy conditions. does a mtb frame provide more balance for slippery conditions than a road bike because of geometry?

any recommendations on handlebars and general setup?

It depends what the roads are like there. If you have potholed or otherwise bumpy roads that will be obscured by snow and ice or darkness, then the mtb will be a more durable and comfortable ride. Otherwise, the road bike will be just fine.

Since it sounds like the Accordo is ready to roll (minus the cog), why not just fix 'er up and see how it plays out? If it ends up being the wrong choice, you don't lose much and you can work on the Royce.

my commute varies from the suburbs to downtown, but there are a lot of potholes and darkness here and there, especially at 3am. the accordo was my first fixie but it lacks a rear wheel. i have a few 7 speed 27"s laying around the house that i could loctite to get it going but that would require me to purchase tires, thus negating the cheap factor. the royce union is actually nearer to ridable condition since it already has the 26" knobbys. i stripped it down last night.
i was actually hoping that the knobbies would fit on my accordo (which they didnt) so that kind of changed my plans.
i was contemplating buying a cheapo 700c wheel but that too negates cheap. im probably overthinking this... its just a winter bike, so i should be frugal. just not looking forward to riding that goofy and heavy royce union frame.

I hear that. There's always a chance that you can find a cheap but quality used mtb frame and just move everything over. My Bridgestone was fully a built up SS for $130 (though one of the tires was dry rotted trash and ended up exploding one morning just sitting in the hallway). If you can find one, I would expect a frame to be about half that. Still not as cheap as you're going for, but in the end you have a decent fixed or SS mountain bike.

Maybe not on the cheapest of scales, but I just built up an IRO jamie Roy for a guy that is using it, right now, as a winter commute/training bike. Using a cross fork and misc. components that he already had. Fitted with 700x37c touring tires. Turned out really nice and he's happy. Took a day before he took off the 45x17 combo and went to a 42x17. Those big tires take a wee bit more to turn over.