[Mako]

I have a design that works well for droping specially made spy satillites.

Ship
Medium Transport
No computers (costs more)
5 engines
1 quantum reactor
1 cloacking device
1 sat bay
1 Mine layer(I edited the files to launch more sats and mines)
Cargo bays
1 solar sail (if you have room)
1 self destruct device (So it won't be captured)

Spy Satillite
Large sat
computer
cloaking device
some kind of sensor (gravitic, phsycic,temporal)

The transport hull makes the ship cheaper. Since the sats apparently have unlimited supplys the cloak can always remain on, same with the ship and it's quantum reactor. I load 10 spy sats and as many mine as it will carry, then deploy the sats some where in an enemy system where enemy ships won't bump into them, like on the edge of the system. I then use the mines to block key enemy warp points too slow down the movements of their ships. These designs have worked so far.

And for a scout.

Escort hull
no computer (size and cost are problems)
6 engines
3 supply pods or 3 solar collecters or 1 quantum reactor (depends on your tech level)
If you have a quantum reactor, equip some weapons or a cloacking device.