Try uShip - The Online Shipping Marketplace - Ship Freight, Furniture, Vehicles or Moves
It worked well for us saving us money and hassle.
I'd suggest not going with the cheapest, go with the best. I wasn't sure if it was better to pay the extra bucks for a more experienced shipper until our boat was being off loaded.
That was when I talked to another guy who had just had his boat delivered from the same area. We compared prices and he saved almost $2G compared to my costs. He was thrilled.
Now that might have been an impressive bit of negotiation on his part if he hadn't been working on his mast at the time. The shipper had driven thousands of miles with a ratchet rubbing the mast. The owner was trying to 'fix' the mast track but it was so badly damaged that it needed a new section to be spliced in. Looking at the other damage to the mast I'd consider a replacement.
Now if it was just the mast maybe it wouldn't have been so bad but there was also the damage to the hull, not just marks (which we got as well but buff out) but actual damage from having the straps and supports rub up against the hull.
He seemed quite happy at the deal he got even though it turned out that the insurance the shipper had was not for damage to his boat and the owner was on the hook for all damage.
I would have been horrified if that had happened to my boat so was very happy to have paid more and saved thousands in repair and hassle.
There is real savings to be had by being very flexible on shipping date and time. You will likley have to pay more if you want it shipped soon and quickly.