Yeah but do they have smooth tops? Are they shiny steel or are they galvanized? Do you know? Alot of carriage bolts out there are made for industrial uses (outdoors, machinery, stuff you don't care how it LOOKS).
Did you even bother to click on the link? All your questions are answered there. Let me state again, I did not shop around. I just grabbed the site at the top of the google search.
The point here is that there are HUNDREDS of on-line places to buy fasteners. You can get what you want for the price you want, if you are williing to do a lilttle work for it.
Go ahead, pay $30.00 for your bolts. In the end, you have your complete cab, and that's what really matters.