What do you need to get the heat down to for stealth?
If you are talking in general, a G5 efficient class A power plant is the most important component, followed by class D or even E clean drives. Efficient engineering is a good choice when using lasers, though as soon as you start firing weapons, you lose the element of stealth for a period of time (there are ways to compensate for this, but this is a trade secret). And of course heat sinks, lots and lots of heat sinks.
Stealth ships are the one build where class E modules offer an advantage, assuming you can handle the nerf in performance. The key to staying cool is keeping power utilization low. In fact, I manage modules (on or off) the way most pilots manage pips.
Now a good pilot will have a few counters to stealth (one is really lame and I wish Frontier would fix it), but I'm not sharing my weaknesses!