Maybe I'm biased but I've told quite a few of my captains about this program, if they had a little more variety with the inland and western river towboats and more options such as regulation 200x35' barges that you could individually put together they'd be all for it.
I'd love to see a little fleet tug, mid size line boat (5500-6000hp) and a full size line boat (9000, or triple screw 10,500)
I've got a few examples of the smaller boats at the company I work at.
1550 Fleet and Canal Boat
http://www.towboatgallery.com/Safety_First.php
6000hp Ohio River Boat
http://www.towboatgallery.com/AEP_Mariner.php
Or my little triple screw fleet tug
1020hp triple Detroit 12v71s
http://www.towboatgallery.com/Safety_Convent.php?pic=2&tnc=1