Any hard ball cricket bat will do.
Two things your might wanna consider.
Heavy tennis ball has quite a high bounce (when u play on concrete), there is no concept of front foot drive or square cut - the ball gets stuck in the grass and just does not travel far enough. So you should look for a bat with high sweet spot which makes the pick-up and feel, a lot better.
A Kashmir willow is more suitable since the ball is made with heavy rubber, you need stiff and hard timber to bang it. You don't need high end soft English willow. It just doesn't make the ball travel far enough.
And this is where the challenge comes.
Kashmir Willow bats are usually not very light. And you ways need a lighter bat for hard tennis ball since the Major shot is hook or pull (due to high bounce if u r playing on concrete).
So do not go for cosmetics or brand name or even a new bat.
Look for an ideally a Kashmir willow bat that is thick, very well knocked-in (if new) light and has a high middle - regardless of name brand, or cosmetics.
I say 2 lbs 7 Oz max with 35 mm edges bat, a used one, will be awesome.
