You have a compatible and solid build.
However I would recommend you to go with 3070/3080 instead of 3070ti. 3070ti is only a ~5% performance uplift from 3070, while 3070 ti draws 290w instead of 230w of 3070.
For ram any ddr4 ram will work. I personally advise you to go with ballistix 4x8gb 3600mhz+, as ryzen platform loves high frequency rams. Micron(crucial) e dies were known for its good overclock ability, while corsair's lower end ram kits are basically garbages while being much more expensive.
Also it would be better to go with samsung 980 pro or WD sn850 to utilize pcie4.0. The 980 non pro has this dramless design, limited both heat and performance, is mainly for thin and light laptop usage.
About the psu, for your exact build 750w would be enough. I would advice you to choose seasonic as its a reputed brand on psu.
Submit photos and a description of your PC to our build showcase
See other custom PC builds and get some ideas for what can be done
Services starting at $149.99