Nvidia 3070 Ti vs 3080

I'm looking to augment my gaming PC rig (now a 24/7 mining workstation) with a second GPU card to exclusively mine RVN.

My price point is in the $700-800 range (ideally up to but not over), and two cards fit the bill: either the Nvidia 3070 Ti, or the 3080. Since I have another Nvidia card already, I'm looking to stay within the brand.

Currently I'm banking around 28.5 to 29.3 Mh/s on 150W; the hashrate went down by around 2-3% when I started CPU mining Monero, and I also host a RVN node; these may not be relevant but I'm mentioning them just in case.

In any case, which card do you recommend as a better long-term investment? Which manufacturers are known for making good products, and which ones are better to avoid?

I understand that the 3080 may have more issues with LHR, and there's unconfirmed speculation that newer models throttle RVN along with ETH.

However, that's not the only issue to consider. There's also power expenditure and overall max output, the latter of which is more important to me between the two since I'll be dealing with relatively low electricity costs.

In addition to the card itself, is there anything else I'll need to support the upgrade? My PC is a new, off-the-shelf midcore Alienware build, so I'm not sure if I'll require a PSU, additional RAM (currently at 16GB), or any other equipment. This is my first time adding a second graphics card so please excuse the noobery here :]

Thank you in advance for your suggestions and help!