Question about boat trailer registration

My husband has me researching this for him and I can't find the info anywhere on the DMV website. He is looking at buying al fishing boat from a guy in Florida. I found all the info on LDWF about registering the boat in Louisiana, but I can't find any information about registering the trailer. The guy told him that Florida does not title the trailer. So, will a bill of sale be sufficient? And, after you get it, do you just go to DMV. I read somewhere else that you had to have State Police inspect the trailer. Any help will be much appreciated.