What do You plan on using for fuel? it makes a little difference in firepot design. Soft coal works well in a firepot about 4-6" deep, coke firepots are a bit deeper. I believe charcoal will work OK in a 4-6" deep firepot, but I haven't tried it, soft coal is easy to get here in Pa. If smoke will be an issue, don't use soft coal.
Is Your powerhammer a sheetmetal hammer or a forging hammer? I am not familliar with the brand.
There are many blacksmithing groups throughout the midwest. You just missed a great event in Tipton, Indiana, including forging a blacksmith post vice using a 200# steam hammer. I missed it too, the guy I hoped to ride & camp with has a really small cramper, and it isn't really set up for more than 1 person yet.