uk mooncup

I am starting to research more emphatically on which cup to buy as my first. after looking at http://menstrualcups.wordpress.com/2008/07/10/cup-images/ and http://community.livejournal.com/menstrual_cups/1285963.html, i decided that a mooncup uk would be a good choice. i came to this conclusion by deciding that i think i'd need a 3 [on the scale from narrowest to widest] out of 6, and a 3 [on the scale from shortest to longest].  the mooncup met both. a 3 is in the middle, and as i don't really know how to tell what i'd need, that seemed like a good choice and i could try it and decide if i need a bigger one or a smaller one.
does anyone have advice for me? what are the reviews on the mooncup? i don't know if i need one that's softer/more pliable or not; i hear the ladycup is the softest, right? i'd just like some feedback to see if that is a good choice.
my info: i'm 18 and a virgin. no health problems. i've been using tampons for about five or six years, because i find them more convenient than pads.
i'd also like to know the best sites to buy this cup [if it's what i choose]. i live in the US.
thanks for your feedback!