Overall, Hayrides and trails are different animals. You need to pick what best fits your needs. You need to take into consideration everything that you will have to construct, what you can leave and what you will have to set and re-set from year to year. For the long-term, you'll find yourself more room to grow with a walk thru haunt, and you will find the capacity of a hayride is limiting vs. a trail. Coordinating a hayride is much more complicated then a walk-thru too.
Food for thought - is this golf course the BEST location for your business? Just because something is free and convenient, doesn't necessarily mean it is the best decision to start a business. Look around at a few other locations just to get a different perspective on things and affirm that the golf course is the best available location. Don't commit something for you to have to set up and take down every night, you'll kill youself and/or crew.
I absolutely believe that you can put more customers through per hour in a walk-thru haunt.
I believe to start-up a hayride will be more expensive than a trail. (tractors, wagons, and fuel are just a drop in the bucket)
I am happy to discuss this with you at TW further.