Pick a site that takes both. Make a neteller deposit and withdraw it to Firepay (or vice versa). Some sites, like Poker Room, require that you've made a deposit with both methods first. If you pay the fee the first time you shouldn't have to pay it again if you're willing to spend the time waiting for deposits and withdrawals to cycle through. But, doing this might piss off the poker room since you stick them with fees each time so pick a site where you already have a good relationship or make sure you play there a reasonable amount before cashing out again.