[Aegis]

Cool Idea.
I'd implement it under the present system as follows:
Escorts, Frigattes and Destroyers are 1 Engine per move, but 2 less Max Engines than now (i.e. 4).
All Cruisers are 2 Engines per move, with Max Engines of 6.
Battleships and Dreadnoughts are 3 Engines per move, with Max Engines of 6.
Ship Construction stays as is, and allows for the building of level 1 ships. It is also a prerequisite for advanced hulls as follows: (Examples for each 3 Category light, medium and heavy)
Escort Ships(New tech area)
-requires Ship Construction level 1
- 3 levels
level 1: Allows Escort Ship II (Cost: 20000)
Max of 5 Engines
50% Defence Bonus
Bonus Movement of 1
155 kT Size
level 2: Allows Escort Ship III (Cost: 40000)
Max of 6 Engines
60% Defence Bonus
Bonus Movement of 2
160 kT Size
level 3: Allows Escort Ship IV (Cost: 80000)
Max of 7 Engines
70% Defence Bonus
10% Offence Bonus
Bonus Movement of 3
170 kT Size
...
Cruisers (New tech area)
-requires Ship Construction level 5
- 3 levels
Level 1: Allow Cruiser II (Cost: 30000)
Max of 8 Engines
510 kT Size
Level 2: Cruiser III (Cost: 60000)
Max of 10 Engines
520 kT Size
Bonus Movement of 1
5% Defensive Bonus
5% Offensive Bonus
Level 3: Cruiser IV (Cost: 120000)
Max of 6 Engines
1 Engine per Move
Bonus Movement of 2
10% Defensive Bonus
10% Offensive Bonus
530 kT Size
...
Dreadnought(New tech area)
- requires Ship Construction level 8
- 3 levels
Level 1: Allows Dreadnought II (Cost: 40000)
Max of 9 Engines
5% Easier to hit
1025 kT Size
Level 2: Dreadnought III (Cost: 80000)
Max of 12 Engines
Bonus Movement of 1
1050 kT Size
Level 3: Dreadnought IV (Cost: 160000)
Max of 10 Engines
2 Engines per Move
Bonus Movement of 1
5% Bonus to hit
1075 kT Size
I wouldn't allow Baseships to be upgraded, but that's just me.
Hmm, cool. I think once the next patch is out I'll mod the tech and vehicle size files and see how it plays.

-Aegis