What I have in mind for this is a little more thorough than a mere six bonus modules.
But I need to have the regular equipment more or less thought out before I get to this that way I know what can be done to what.
The idea in this area is to think like an RPG gamer. Shield Gen booster of +4, Cooling Pump of +2, Magazine Capacity +5 (ten percent). That kind of thing.
You should have room for standard equipment plus 3 - 4 of these, or less equipment and 6 -7, or more equipment and 1 - 2. But there will be enough subsystems in the complete list to add plenty of combinations so it doesn't get old.
Shall I create lil army men