I always bought stuff that was on clearance at Petsmart for my kittens. That way when they outgrew it, it wasn't a big deal because it cost under $5...
Sphynx do get cold if you do not have the heat on. I did look at the clearance at petsmart and did find one thing for her but she has to grow into it. When I take her to the vet I wrap her in a blanket because its to cold for her. Maybe soon I will find something that fits her right.
What kind of pet stores you have there? I wonder if one of my vets would know. She is from Australia and she loves Cleo. She also takes care of two rexes that come in.
the fleece I use doesn't cover so much of the body since my Sphynx has heated beds she spends a lot of time in when cold. but also since the coat is made for a small dog and doesn't have as long of a body as my sphynx and is built differently and it leaves plenty of room for her to go to the bathroom and mess around in the litterbox without getting the fleece dirty.
here is what they look like http://www.gollygear.com/fido_fleece.htm
these coats look like they are easy to make if you are good with sewing. Just buy some fleece and custom design.
In Aus we have an awesome pet store called Pet Stock and there's a few diff "pet barns" but no major chain. I wish I could sew cos clothes here are so expensive!
My cats don't mind putting the clothes on, or wearing them. They just act normal. No bloodshed or I'd give up pretty quickly.
A friend of mine owns a pet store, she adopted one of my foster kittens and she said that Teckelklub brand fleece jackets fit really well for cats. She had a photo online of the kitten wearing one.