Okay, let's assume we're talking about recon task in hostile teritory.
As we want to stay undeteced as long as possible,
we need some stealth, to minimize the range at which we could be detected.
also we need strong sensors, with a huge range for passive scanning.
(active scanning would act like a beacon, rendering stealth useless)
We need a ship, wich is able to travel a greater distance without the need to refuel.
Hornet Ghost: one of the best ships, when it comes to stealth, but range and scanning power may be an issue. Can defend it self, when in trouble
Herald: good range and awesome scanning abilitys, but stealth may be an issue. can defend it self for a while or at least cover it's escape with some data spike missles, before it burst away with it's big engines
Freelancer DUR: awesome range and great scanning abilitys, but the stealth could be only medicore (huge crosssection, as it's not a small ship)
When in trouble, it could defend it self for a while, due to big shields and thick hull
315p: good range and good scanning abilitys, the stealth could be not that bad, due to (sleek design and it's a small ship) can defend it self vs non fighter ships, but should run, when dedicated fighters show up.
sabr: simillar to the hornet ghost, but the range may be greater.
I don't think there is the single best ship for each situation, but if i'am asked to scout out ennemy movements and comunications, i would choose the Herald. As we only know little about ship customization jet, i only talked about stock ships (or what can be expceted for a stock ship)
PS: to turn a sabr into stealth mode, turn of the engine manually (stealth is not implemented propaly jet)