Has anyone installed an electric jack on their horse trailer? I am interested in hiring someone to install one and I have seen multiple brands online but a couple reviews said that they purchased one and it wasn't enough to lift their trailer up. How do I go about figuring which one is heavy duty enough for my trailer?

I'd go thru a trailer dealership and pay the extra money to make sure it's done right. Before we got our new trailer with electric jacks, we priced out what it would cost to have one installed on our sundowner, he quoted us $1200. Its well worth it, in my opinion! I love our electric jack. 

I went through a trailer dealer/service for mine. Mine is a Big Foot. Best investment ever. I would just find the closest dealer or place that services them & get a quote. Any RV/Camper place should be able to handle it as well 

Our 32 ft. Living quarters has one but I keep telling hubby and boys that they need to get me one for the little 3 horse.  Even though it is only 16 ft long it cranks down harder then up.  Electric jacks are the best thing since sliced bread!!!!!

My husband and son intalled a Bulldog 12,000 lbs. Electric Power Jack on my horse trailer in just a few hours.  I have a  Featherlite 3 horse with a 7' LQ.    There are plenty of Youtube videos for reference.  They installed it in such a way that even if the battery is dead, I can stall crank lift or lower the jack as needed (still has the bar).  He paid around $500 for the jack. In our area, a Hydraulic Jack costs around $1,000 installed. 

Good luck!