You can buy one in a crate, from your salesman, through the program called Whole Goods. Just like buying a new tractor. Do not order through the parts guy.
The installation is pretty darn straight-forward, especially if the Valve Block is already installed, which it should be. You can also buy the 203 loader and save a wee bit of money. It will 50-60 lbs less lifting power, but it is quite useable and has plenty of grunt for the BX. The 243 might not be priced different enough for you to be concerned at all.
IIRC, my FEL in a crate was $2200. Shop around, get quotes, and barter and push, just like you would in buying a tractor. If you're in a hurry, the dealer might have a FEL in a crate, but if you're not in a rush, the dealer can throw it on the truck with his next order incoming.