The usual form is "(to) love (someone) to bits"; "(to) love (someone) to bits and pieces" is a less common variant ("bits and pieces" is another set phrase, which means "a collection of disparate things").
I can't think of an exact synonym. "I love you to bits (and pieces)" implies "I love you very much" + "I love even the smallest part of you".
The phrase is often said with an intonation of extreme relish. People say it about pets and children too; to my ears, it has the same atmosphere as e.g. "he's so cute I could eat him".
I think it's probably safe to say that, on the whole, the phrase is less used by men. (But I'm happy to be corrected.)
All the best,