I've tried to read through everything but I'm lost still D:

My rears are slowly losing their tread but my fronts are still excellent so I need to order some new rear tires eventually.

They still have the stock tires.

Would it be better to just get all new tires all around?
Or just get new oem's for the rear?

Now that the weather is getting really cold and snow's just around the corner, I'm debating if I want to get some all seasons (though this car is mainly a weekend car).

 

I'd just replace the rears with oem tires and it should work out so you will have to replace all four next time...then decide if you want to go with a different model or not.

 

im in the same boat,....the oems just dont hook up in the cold,.....so i dunno what to do either.

 

If you are looking for better cold traction you would need to go with an all season tire or a winter tire. If you go this route you should go with all four tires. Otherwise just match the tires that are on the car now and make the change to something different the next time when they wear out together.
If I can help let me know.