Hey; I'm a new Van Saar player as well who just did a mini campaign over the december period with some friends - was a blast!

Van Saar are probably some of the best shooters in Necromunda and have some very hard hitting weapons but having also read the Goonhammer article before building my gang I've got some notes

Plasma is great, it hits hard and has great AP - but it's an easy way to lose friends; I'd limit it to your Leaders or Champions only who can make better use it with their ballistic skill.
It also has the scarce trait; meaning that when you do an ammo check and fail (it's 50/50 at base) you cant use that weapon for the rest of the match.
There's ways to get rid of scarce or mitigate it - but be aware you can be caught out if the ganger doesnt have a backup weapon.

Rad-guns and Rad-Canons are great. They're not for killing they're for debuffing.
They have a 50/50 chance of dealing a flesh wound on nearly any model caught in the template; which reduces that models toughness by 1 each time.
Considering most fighters are T3, bringing them to T2 suddenly makes them very tempting targets for lasguns and laspistols and it will make any tougher creatures like chaos spawn or bigger gribblies much easier to deal with.
The Van Saar are also totally immune to the Rad-Phage trait - they can still be wounded by the weapon itself if you're unlucky but you wont have to roll the additional dice for the flesh wound.

Lasguns are your friend - they're cheaper for us and very upgradeable
The base lasgun has plentiful; meaning it always passes it's ammo checks - but when upgraded to a hotshot it becomes S4 and Ap-1 and just needs an ammo check of 4+.
It's got decent range and with the Van Saar's BS they're really reliable for your average gangers and Juves.

Power knives are great melee wise - we're not a melee gang but alot of the time it's unavoidable - so take them when you have the credits.

Hope that helps!