Greyline are the best after market bait wells you can buy in just about everyone's opinion.
The best aftermarket tanks have the best filtration, aeration, and insulation. Greyline has one of those...insulation, which is the least important IMHO. Creekbank, Superbait tank II, Sunshine, Bluewater, and Clearwater have better filtration and aeration. I'm not sure which of those are still in business but if you can find one with similar aeration and filtration with no seams that's your best bet. Sunshine bought out Greyline a few years ago. If they incorporated Sunshines filtration and aeration into Greylines mold then I stand corrected.