>>1091224 the tarp and the length of the hammock goes a long way. personally i run with a chill gorilla hex because its massive and can last horrible storms. as far as hammock length goes (assuming you're around 6ft) i'd go with an 11ft hammock. if you're starting out though, just buy a cheap parachute hammock for under $20. and if its winter like you said, you'll need an underquilt and topquilt (or a sleeping bag if you have one already). hell, even in spring or fall you need an underquilt.
and for the love of god, use treestraps
pic related is me in my hammock. planning on moving to a larger hammock whenever winter comes around.