By far the most powerful winch I had for 6 rigs is the Fulton XLT...about $100...
BUT if you need it you need it...about an 11 inch handle and 5:1 ratio...

IF winching is a serious issue due to boat wt, angle of launches or physical strength also get those Ultimate Bunk Bds for your outside five ft boards...they are synthetic and your winching will be 3x easier at least...been there with 2 rigs...I like.