What do you think would be a good mixture of environmental/good teepads?
Environmentally friendly? I don't think there really is such a thing....every type of teepad has something about it that isn't friendly for the environment - including no teepads. The big issue with teepads is that "everyone throws from that spot". Elsewhere on the course you see less wear and tear due to the planting/twisting of the foot because discs don't land in the same spot for every player. ((Disclaimer: there are spots where discs commonly land -C1 for example - that can cause lots of wear/damage on the ground)).
No teepads: the ground really gets 'chewed' up by the run-ups and planting/twisting of the feet. Then it becomes "nasty" looking.
Concrete teepads: last longer. If you put grooves into the concrete, it provides better footing. Eventually wears down. Hard to replace. This is the easiest overall (for consistency between teepads), which is why it is used a lot - concrete can be formed in whatever pattern/shape you want the teepad to be, round, square, hexagonal; it can be easily leveled, it can be patterned to give good footing/traction. Good and bad...it is near impossible to move - it won't move while you are doing a run up, but if you need to move the teepad elsewhere...forget about it.
Pavers/bricks: last longer, easier to replace/move. Can shift out of place.
"Astroturf"/rubber pad: wear out quickly, can bunch up causing footing issues, also can get bumps and divots from run ups and where players commonly plant their feet. Easiest to move/replace.
Personally, I think pavers/bricks are the best looking....but more difficult to create. To keep them from shifting, create a wood frame and put the pavers/bricks inside that. You also have to put in extra work to make and keep them level.
If you think you will have to move them alot....go with "Astroturf" or rubber. Test them to see which will hold up better in your area and cause less slips.