I can't seem to find the 670 available new for sale with a quick google, what would you suggest I buy instead? everything else seems to be lower end or hotter.
Probably I wasn't clear: as far as I know the GTX-760Ti is a GPU which is equivalent to a GTX 670, and up to now it has never been seen in the retail market.
Broadly speaking the GTX-670 is slightly hotter and not significantly better performing than a GTX-760 (I mean: the non-ti version): so, as that GTX-760Ti should be that similar to the old GTX-670, it seems worthless to consider it.
One of the most comprehensive source for video cards reviews is TechPowerUp!, so you may rely on it for your comparisons, but I like also HardOCP about performance assessments, as well as HT4U.net (a german site) or Guru3D, but there are many ones.
About performance levels, priorly you should state your gaming resolutions (your monitor' one, usually), and then your favourite racing games (F.1 20XX, Dirt: Showdown, whichever): with those data, scan the web looking for useful data and gameplay videos, maybe using some search terms as, for instance, "F.1 2013 benchmark" (just as a guess, coming you off console-like performances, I think you will hardly be disappointed by a minimum speed of 45-60fps at your resolution).
So, have you already done that?