I am getting the gtx 1070 ti for £310. It has more vram so won't it be more future proof?Unless you are getting it for less than the price listed there, I wouldn't go with a 1070 Ti at this point. It's from Nvidia's previous generation of cards, and their newer RTX 2060 offers a similar level of performance in current games for less, and has updated architecture that may help it perform better in future titles.
Okay, I will be getting the 1070 ti as it has a year warranty. Is the Kingston hyperx 3200mhz compatible with the ryzen 7 2700 and b450 tomahawk?Which card will be more future-proof is a bit difficult to say for sure, and may vary from one game to the next. It's certainly possible that the extra couple gigabytes of VRAM may help performance in some future titles.
On the other hand, the 2060's updated architecture is likely to provide better performance in games that make use of newer APIs though. And of course, the 2060 features raytracing hardware, so as raytraced lighting effects become more common, enabling them won't tank performance quite as badly on the RTX card. It's a bit questionable whether this first-generation of raytracing hardware will be powerful enough to make the effects worth enabling though.
Either card would probably be a reasonable option around that price. If it happens to be a used card, you might also be giving up warranty coverage with the 1070 Ti though.