The stealth armour only gives you protection against lv1 active and passive EM scans. But it does bump up your damage resistance and defence bonus into the bargain. The cloak just gives you progressively higher protection against lv1, 2, 3 scans. My advice is to combine scattering armour with a cloak - same defence bonus, same damage resistance per Kt as stealth armour, but cloaking is left to the cloaking device and the scatter armour stops any long-range scans (handy for keeping your new secret weapons secret until you want to use them).
Note, you can also stack stealth armour with scattering armour and the defensive bonuses will stack up

Add ECM III, mwahahaa. But 90 kt in total, pretty heavy, you can get a couple of shield generators for that much.
[EDIT] My personal fave is to put scatter armour on my star-killer ship. It's for that 'Oh Boy' when it de-cloaks right over their system star

You can empty a system real quick this way and not even fire a shot.... of course nobody buys a bluff like that.
Everything works on a per-ship basis though, so if you want an attack fleet to sneak into enemy space to do a little bit of napalming of defenceless targets, gonna need a cloak for each ship.
[ June 19, 2002, 20:02: Message edited by: Marvin Kosh ]