It's all personal preference... but if you're buying ONE, you should go with:
The 1/48 VF-1S: Nothing like that yellow/black true-to-life Skull-1 color-scheme. I even prefer it over those overrated low-vis dealio's (the only thing those got going for themselves is the availability and low production issue; and because of this, everybody wants one... and, of course, the price. Hell, if you want the same effect, buy some gray paint and spray the frakk out of it.... that'll save ya some $$$$).
Be cool, like me, and get the ONE and only VF-1S.
And yes, the armour is a seperate buy (well, unless you get the VF -1J or the other upcoming "series" type)
Here are some direct links:
1/48 VF-1S
1/48 Fast Packs
There are also sticker sheets you can buy so you don't have to ruin the ones that come with it. Get ready to pay about $200 for all of the above (to me it's expensive, but well, WELL worth it)... hence, the reason I only own one. But I love it!