Долго выбирать - замужем не бывать

A too fastidious person will never find a spouse

Var.: Много выбирать - женатым не бывать

Cf: The girl that thinks no man is good enough for her is right, but she's left (Am.). If you always say "No", you will never be married (Br.). If you want to stay single, look for a perfect woman (Am.)