Different feetpaw materials?

I'm currently using gym mats for the bottom of my feetpaws, but really would like to update to something sturdier/better or even the best. The gym mats I currently use have big bumps in them and make it difficult to work with/come out as I'd like.
I've been hearing a lot about a flat rubber-based material as a better alternative?

I do most my shopping online, so stores are really out of my reach or question...

Would anyone be able to link me to an online high quality mat/rubber material that works great? Can be from ebay, ect.. Looking for multiple alternatives really

Thanks!