Idea for a livewell? Opinions....

One of the main reasons I haven't caved and gotten the Hobie Livewell for my PA is 1) Its expensive 2) More to maintain 3) I love my yakpak and hate to give it up.

So, I've come to a possible solution.
I have this empty jug which measures out to exactly 2 gallons. Obviously I wont be able to keep a TON of bait in here, but a few macs and a few dines should do ok with proper flow?

It fits perfectly inside my Yakpak and leaves me enough room to still fit the things I carry anyway (Foul weather parka, lunch, water bottles ect....)
I love the yakpak because it keeps everything I need safe for surf launch/landing, it secures the the boat easy and has all the essential rings to secure my stuff to it. Plus the pouches all come in handy since the PA has practically no storage outside of the center console.

I was planning on just putting a small pump on it, and a drain hose that would go right down into the scupper, which is just under the yakpak.

Is 2 gallons enough? Can I get away with just an airrator? What size pump should I use? Is this a stupid idea?