A six row would be substantial. Nothing wrong with an eight row either, of course the eight would require a little more truck power than the six. A grain cart is an absolute must. Doesn't have to be the biggest or the prettiest. Just something to transport the grain from the combine to the truck and to keep the combine moving. As far as a combine goes, any one will work. JD, Case, Gleaner, NH, all supply good machines. Just make sure to get one that has been well maintained.