"Hottie" is generally defined as "an attractive person." See, http://www.geocities.com/online_slang_dictionary/slang/h.html#top

I have heard it used to refer to both men and women, and, at least in my experience, it seems to have more frequent use within the gay community.

"Hotsy totsy" is defined in Webster's as "about as right as can be", and Webster's says it is said to have been coined by a US cartoonist. I can see a possible relationship between the meaning of hotsy-totsy and hottie, but I can also see a possible relationship between the slang "hot," meaning attractive, and "hottie." Maybe they are all related.