Its the same deal as with the 22 Buggy. You don't need 'special' short lipos.
If built in rear motor configuration then you can run either full size stick packs, saddles or the short stick.
If built in the mid motor configuration, you can run either saddle packs or the short stick without any issues.
With a short servo, in mid configuration at a push, you can run a full size stick pack but you would need to design a tray to fit your rx and esc that would sit above the battery.
So no need to buy anything else
HTH