Li-Ion Batteries

Hi, I’m looking for a 3S or 6S li-ion battery to pair with my quadplane. I will be powering the quad motors with a separate LiPo battery. We’ve been using 6S 14000mah li-ion batteries to fly the plane alone, but we’re now starting to convert it to a quadplane, and these batteries don’t have a shape compatible with the LiPo we’ll be using. By compatible, I mean we have a limited amount of space where we can shove these batteries. We’re using a Scorpion SII-4020-420KV for the plane side and our system averages 45 Amps while flying from looking at the logs. So I was wondering if anybody knew a seller for li-ion battery packs in the USA. I also know of
But, from what I see their continuous amp draw of most of their batteries are ~20 Amps. Anyone have any experience using these packs, and what amperage are you able to go with them.

Also, our MTOW is 10kg.