Liquor vs beer/wine ect

I'm on a limited budget and trying to figure out the bar situation. I have 50 guests and was gonna do a beer/wine wedding, but I have some questions. How do I make sure we don't run short? (Some of our guests drink a bit...) is having a cash bar as an option for people that don't like beer or wine (myself included) how do make sure people aren't going crazy on the free alcohol since I hear tickets are in bad taste? Any advice on the liquor element is appreciated. Also, I don't want a "signature cocktail". I'm too picky and there is a lot of gender disparity on drink tastes in my group.....