Rightyho. Shouldnt think Garqi is dramatically well defensed, most of its defenses will be tailored to anti-pirate defenses and suchlike, the main bulk of the actual defenses being planetside.
I would like to put one Cardan-II-class Space Station there, the 'Bulkwark of Industry'
Two Corona-class Frigates 'King of Garqi' and 'Garqi's Pride'
Pesktda City Defenses
24 TIE Interceptors
2,100 Stormtroopers
23,000 Imperial Army
Rest of the planets defenses
28 TIE Fighters
10,000 Imperial Army (split into 10 large garrisons spread out in cities and also 2 in remote locations)
Those are the numbers for the troopers, they would also have vehicles, but not in great numbers aside from the Stormtrooper unit (aside from the troops having ready access to repulsor trucks etc with ghetto-rigged armour and such.
Regards,
Jamie