for links you need shield/armor and skirmish, although you could do fine with just shield/armor but skirmish does add some tank. also without links your 2 basi might struggle with tanking core strongholds if you plan on doing those, strongholds have a wave of 2500 dps with high volley and the basis have a EFT dps tank of 1900 omni dps, thats of course not counting the low signature. With shield links that tank goes up to 2500 and the sig goes so low that the cruise missiles barely put a dent in you compared to the ishtars.

For running without links i would go with guardians, that 70m really makes it tank nicely.