Hi Onit. The CannonMikes replica looks pretty nice but the pictures aren't that clear. The one on gunbroker looks like a pretty strong carriage with nice wheels but its a lot smaller than it looks in the picture. The price seems OK but its not my thing.
Graystar has very affordable cannon barrels but im not a fan of cast iron at all.
I would use one of the sponsors on this forum and if you can get a 24 or 32 Pounder in the size you want on a Duel Trail Prairie carriage for a thousand bucks you would be getting a good deal. Good luck and I hope someone on hear can help you.