Gauss is a very flexible frame. For survivability you have passive/operator/kinetic plating, and so for mods I would only recommend [Rolling Guard] if you feel like you really need it. Kinetic plating maxes at 100% ability strength and is the only ability that really wants strength so there's not much reason to mod it other than helminth/low level nuke. Balance the rest of the stats however you like.
Notes
The polarities for this build are different from usual so you may prefer this on a second gauss or make some compromises.
The subsumed ability for this build is intended to be a buff that doesn't require being spammed (if you pick something to spam you may want to drop energy conversion for efficiency).
Augur secrets can be swapped for efficiency/duration/flow if you prefer.
Roar can be replaced with any other subsumable ability that works with the stats.
Aura, exilus, and arcanes are up to user (you might find growing power relevant but will have to forma for it).
Other Builds