This depends on wether it is a med or low tech start game. If med tech start than stealth armor shows up REAL early, low tech is costs more as Chemestry must be researched first. My own solution is to go for Military Science II as fast as possible, then develop the....the....brain fart, can't remember what it is called but Military Science 2 gives you access to the tech that allows you to do Fleet Training and Ship Training facilities (think it is advanced Military science???ugh 4am, can't think), but Hyper Optics is the 4th level of this, and all you need is Hyper Optics I and you can see stealth armor ships (launch sat with Hyper Optics I component, 1 per system)...This IMO is much cheaper than going for Grav sensors or others, plus you get the Training facilities, wich are necessary to survive.
Otherwise, go for mines as soon as possible.
Other strategies I find good are to have Weapon Platforms and Sat's on planets, or go for Stealth Armor yourself!
ok, time for bed
