[Marty Ward]

I would take one of the computers off and, something else if you need more space, to fit the sensor. Not to good as a border patrol if someone can sneak by.
With you machine shop only repairing one item per turn if it gets into a fight and takes some damage you may lose the use of the emergengy supply, but it's not a necessity to replace.
One stealth armor would allow you to patrol the other side of a warp point without being seen by everyone but I think I read somewhere that mixing armor types isn't good so it might not help.
While you seem to have a lot of shields, it depends on who you are fighting. You know best who your most likely opponent is now but the armor is useless against the crystal and I have seen many AI's use the shield depleters later in the game. I have had 5 Shield V's go down in one combat round.
In my opinion the best defense is a good offense. If I were to make this DN my main combat ship I would definately consider making two models. The current one for the front line and one would have reduced defense and some long range direct fire weapons, after all with the talisman you never miss.