At the moment I'm not too sure about levelling, the numbers they cover or its physical occupation.
So I threw together some ideas.

---

Suite: Example
Cost: 500mc
Tech/skill lvl: 1
Size: 1/2 crew quarters
Equips:1 platoon
Details:

Upgrade cost: 1000mc
Tech/skill lvl: 2
Size: Full crew quarters
Equips: 1 platoon
Details:

Upgrade cost: 2000mc / 3000
Tech/skill lvl: 3
Size: Full crew quarters / 2 crew quarters
Equips: 1 platoon / 2 platoons.
Details:
(Special: For 1000mc extra you can take advantage of our double up clearance offer. Buy one get the second half price. Twice the equipment, taking up twice the space.
effectively two separate lvl 3 suits to be upgraded individually. Specialty cannot be purchased later.)

Upgrade cost: 4000mc
Tech/skill lvl: 4
Size: Full crew quarters
Equips: 1

(Specialty: pick one.
1,
2,
3,)

---

The amount of 'troop companies' a ship can hold limits the number of troop based 'suits' you can have.
Troop company = 1 crew quarters.
A suite occupies crew quarters. (But otherwise has no effect on number of platoons a ship can hold. Shared space.)

---

Suite: Conversion to quarters
Cost: 200mc
Tech/skill lvl: 0
Size: 1 tank/mech/fighter hanger.
Equips: 0
Details: Replaces a hanger with crew quarters but prevents installation of any suites.

Suite: Conversion to quarters II
Cost: 5000mc
Tech/skill lvl: 0
Size: 1 tank/mech/fighter hanger.
Equips: 0
Details: Proper utilisation of hanger space allows for one of two options:
Special: Pick one.
Option a, this hanger now can hold two troops. (But no other suits.)
Option b, this hanger can hold one troop and a 1/2 sized suite.