For op
Some tips for building street sam, at lease from my (limit) experience/opinion.
try to buy as much as 6[8] active skill with skill point or at lease in one primary weapon of choice (6 base skill + 1 for specialize)
you can get 6[8] Automactic (SMG) which worth 49 karma with only 7 skill point
On the other hand, 1 rating skill worth only 2 karma, which you should avoid buying with skill point
For other low rating skills you need, buy it with karma (at low rating, it's very cheap)
It's maybe depend on GM but most used skills in SR are sneaking and perception, don't leave chargen without them.
Try to have a wide range of skills, not just fighting skill.
Ever 1 rating with 2 attribute can make the different between critical glitch and success.(for task that only need 1 hit, of course)
Does your group has someone with skill in pilot ground craft?
if doesn't have, you should have them, most street sam has high reaction, they can be a decent driver.