This is where i got mine. I think I paid about $30 for it. It was not custom but one of their standard sizes that fits my 16 gal kettle perfectly. It's very strong with the webbing reinforcement with loops for attachment. I put caribiners in the loops and that's how I hang it from my hoist. I've had almost 40 lbs in it with no issue.
I tore mine on one of my sight-glass screws and sewed it back with heavy thread. It's been fine ever since.