I got a 48 inch box blade from Midwest, it's great. I've got a BX2200, but I'm sure the BX1500 will pull it just fine. The lower weigh model blade (15 series) is very sturdy and weighs about 310 pounds. Cost me about $335.00 delivered. I would highly recommend taking a look at their's. Check out the three point link assembly then go look at the local stores.
I rented a 48" box from local Kubo dealer. It worked no prob.
Hell, the only problem was traction with the turf tires. Plenty of power on tap..... /forums/images/graemlins/cool.gif