picking a yarn - rep weave

Hello! I am taking my first stab at rep weave. I am planning on making coasters. I am interested in hearing people's thoughts about what yarn to use for the warp. I am planning on using cotten, but am unsure of the size. Would carpet warp be a good idea? Or 8/2?

Also, for the weft I was thining of bundling together some carpet warp or using Peaches and Cream. Do those seem like reasonable options?

I'm not sure if anything of these things matter or if there are specific things I should consider when picking a yarn for this project.

Thank you so much!