Shader with UV mixing and UV scrolling

I need to make a big lava lake, but having trouble getting it to look good. I think I need:

1) UV mixing to minimize texture tiling. (The lake is about 500x500m.)
2) UV scrolling so the lava surface slowly drifts past the player.
3) Emission so the lava glows.

Shader code is a mystery to me, and I can't find anything on the asset store that does all these things. Anyone know of any available shaders that would accomplish this?

thanks!
Dave