Boom Shack-A-Lack ?

Just a quick question. I am nearing the end of my Empire painting queue. I am 2/3rds of the way through my final unit, the Helblitzen. After that, just 2 hero models to do. Then the cannon. But what cannon, I do not want to go newer than 4th edition, and as it happens I really quite like the 4th edition one (except the wheels): But I don’t have one and ebay prices are quite a bit more than say some alternatives from Wargames Foundry: I am struggling to decide which way to go, what would you oldhammerers do, or indeed what did you do? (Next blog post the finished Helblitzen!)