Bill,

Do you currently get away with a single pass with the disk and a single pass with the field cultivator in your corn stalks?  Even if the answer is yes, I'm hesitant to say that you'll be happy with a 724 or 726 and a single pass.  If I were you, I'd look for one to rent for this spring and see how it works in your conditions.  Even if you have to rent a newer one than you are planning on buying, you'll know how it works in your particular situation.  There's just too many variables to be sure from here.

Good luck (I'd be interested to hear how you get along if you do buy or rent one.)

Mike