Hi John
I run one pump off the main battery as it doesn't get an awful lot of use and so can easily cope. Last time I was there though I was tempted to add a leisure battery, quality at a good price. If / When I do buy one it will be from here.
Speak to the boss, I can't recall his name but they're only a small firm and he's always there. Tell him what it's for and he will point you in the right direction.