For VHF set-ups, it really depends on what you are comfortable with.
For guns two main things to note are:
a) Speed of gun.
b) Fire rate of gun.
Most people aim well with 4.00 refire 700ms guns. I on the other hand, am terrible with them but am good with 8.33 750ms guns.
Also note that to take down shields, usually people grab a few debilitators. The usual setup for most ships is therefore 2 debilitators and 4 hull-busting guns.