Thanks in advance!

I use the Weapon Stats for the Installd Laser (mostly Turbolasser with linked 1 or 3)

and the Stats and skills of an habour security guard or an impereal fleet officer

As Nightone said, using weapons off the CapShip should be good enough for any planetary/base defense weapon system.

I just used this:

http://swrpg.viluppo.net/transportation/vehicleattachments/1918/

(the "ground buzzer" vehicle weapon from FLY CASUAL)

and assumed it was attached to the ground and not a ship.

There's some fixed artillery in Lead by Example, but you can make a pretty basic formula to generate your own:

1. Decide what you want you air defenses to look like
2. Select a vehicle of appropriate size for the weapons/systems/functions you want.
3. Remove speed and handling
4. Add weapons, adjust armor/HT/SS if needed.
5. ?
6. Profit

Example:

Guardian air and low orbit defense system

Networked system composed of several launchers, a sensor, and a command post.

Speeder Truck for the launchers, Landspeeders for the Sensor and command post

Remove speed and handling

Add Concussion Missile launcher to truck, Sensors: Long to sensor, Armor 2 to command post.

Or

Forge Hammer relocatable gun system

"towed" system composed of a generator and a manned gun system

Landspeeder for the gun, Speeder bike for the generator

Remove speed and handling

Add quadlaser to landspeeder.