The Perlite of choice is Industrial A light or a bit stronger and heavier choice is Industrial A Heavy.

Both are like course sand and used in applications where light weight is important.

For vermiculite Pool Pad is a great choice.

All the above come in 4 cubic foot bags and are usually cheaper than the garden center varieties so worth looking around for.

In fact you can buy a Readymix of Pool Pad Vermiculite Portland cement and admix.

It's used in swimming pool construction.