Do I need a women's or men's board?

I'm a mid-20s female beginner boarder (and snowboardingforum lurker) who boarded three days in last years season. I didn't do too badly and was handling green runs and some blue runs, although I definitely need more time on the hill to improve my technique and style. I got addicted and have been checking out gear and waiting for the snow season to start here in Australia. My goal for this year is to try out anything and everything on the mountain as often as possible.

For the upcoming season, I'm looking to buy a board (while I'd like to have all the gear, I'm not sure if I can afford to buy it all). Last year I rode hire boards (a 145 Endeavour Guerilla 2008 and a 147 Rossignol) and they both seemed fine. I'm not 100% sure what I want yet, but I like the look of the Never Summer Lotus and I was considering buying a 149cm board.

I've been looking at posts on this forum and just realised that my feet seem to be considered big for a woman (based on Internet converters).

Height/Weight: 5' 3 1/2" ~170 lbs
Boot size: 8.5-9 AUS (I think this converts to 10-10.5 US).

I've been looking at women's board, but have been a bit worried because my weight seems to indicate that I should be riding ~153cm boards. I didn't seem to have any problems with the two boards I rode last year.

Now I'm really confused after reading way too much information. Should I buy a women's or men's board? Should I buy a longer board than a 149cm? Should I buy a board at all or just try out different hire boards this season until I know what suits me best? Any advice?