Prix fixe dinner or not, which would you do?

I am trying to figure out what to do for my wedding dinner. We are getting married in Vegas and instead of a actual reception we are going out to dinner afterward. Now I have two choices as to how to handle this. We can pay for every ones dinner and we will have a prefixed dinner with three choices, steak, salmon, or rigatoni pasta. Not the best choices but it is what we can afford. People would be paying for their own beverages if they want something alcoholic. The other choice is to have people pay for their own meals and they will be able to order anything the want on the menu. It will be about 25 people or so, so it will be a large group but going to dinner is something that we are letting people know that we are doing and they can come if they want to. Which would you chose and how would you let people know if you chose to do the people paying for their own? We are sending out invites to the wedding but only because there are certain people expecting them if that makes any sense. Oh also the restaurant that we are going to is a little on the pricey side but not completely outrageous