The 100 MSP is going to be for the geosensor. And I never make a pure geosurvey ship military. There's just no point. The only thing making it military is the choice of engine (and that active sensor).
If I'm going to do a military survey ship, I'll put geosensors and gravsensors (and thermal and EM sensors), a good fuel range, enough engineering spaces to give it a 3-5 year maintenance life, and usually its own jumpdrive. I might uparmor it a bit, but only if my armor tech is good. Otherwise, I just accept that they're expendable and expect to lose several over the years. If I've got good gauss tech, I'll stick a CIWS or two on them, which can sometimes save you from one of those situations where you trigger some long-forgotten Precursor missile salvo on a planet.
If I'm feeling fancy, I'll do three non-jump capable scouts and stick them into a single large jumpcarrier with plenty of armor and point-defense. Pop into a system, deploy the scouts, let them do a full gravsurvey and basic geosurvey (just interesting planets), then load them back up and jump to the next system.
I was bummed to find that my idea of using geosensors on missile/drone-delivered buoys won't work, because you can't target planets from distance.
Hmm to do the geosurvey? I just read a "lets play" on the goon site where the guy did exactly that - the trick might be to target the missile on a waypoint on the planet? "Click on the planet, go to the other screen and use 'last'" is the bit I remember. I meant to give it a try in my next game, which I HOPE I can hold off til 5.70 but reading AARs is making me impatient
Hmmmmmm....I tried that, but the problem is that planets move, WPs don't. Never could get the buoy to deploy on the planet rather than just out in space near the planet. There *is* a "Fire Missile At Planet" command (used for planetary bombardment), but you have to be in orbit to use it, which defeats the purpose.