The 3060 Ti is rumored to launch soon, and probably either at 400$ or 350$.
We don't know if it will launch in december, but I personally think it will.
The 3060 Ti, if it follows the trend of the other 30 products, will be probably between the 2080 and 2080 super.
which is a bit faster than the 2070 super, but not a whole lot.
If stock is "fine", and the MSRP the actual price, I think the 3060 Ti is the one to get.
The 3060Ti will use different silicon, unlike the 3090, 3080 and 3070 that all use the same die, and practically come from the same wafer, and just are divided by binning, where the worse one goes for the 3070, the good one goes for 3080 and the best goes for 3090.
Meaning it might have a better chance of being in stock.
EDIT:
Sorry for my mistake, the 3070 (GA104) is actually different silicon from the 3080 and 3090 (GA102)
The 3060 Ti then will probably use GA104 too.