320 gives you Rookie Runners, in effect... they could easily be people fresh off the real world that have fallen into the shadows, they could be up-and-comers, but it also allows for grittier people, like your classic razorgirl or a corporate face-type who moonlights in seedier areas to start his Mr Johnson career path.
What I use for 320 is as follows:
320 BP, up to half of which can be spent on attributes (Thus, 160, or a 3 in everything) ... as usual, points spent towards Magic or Edge do not count as attributes.
Up to 40 BP can be spent on resources.
Gear is capped at Rating 4, or Availability 8, whichever is less.
Skills are capped at 4, but you can take one skill at level 5.
Skill Groups are capped at 3,
Contacts are capped at 4 loyalty and/or connection. (Thus, you coudl have a 4/4 contact.)
Adept abilities are capped at 4.
The GM reserves the right to thwap you and deny any cheeseballing. (IE, taking the inability to pilot anthromorphics is unlikely to get you 5 points, chummer.)
From there, you're pretty much good to go. I can post quite a few sample characters if you'd like.