There are plenty of threads on this on the forum, but most are pre-season 7, so don't contain too much useful information.
What is better for a DPS escort, the MACO or the Omega set? On one hand, the MACO set increases survivability, which is good, but one the other hand, the Omega set allows for a greater degree of DPS, so I'm conflicted.
The old 3 Borg + MACO shield option was good pre-S7, but I'm not sure what the equivalent mixed-type set would be, especially consider STF play.
Omega engine + deflector to get the extra speed, targeting bonus, and Tetryon Glider. Then you just pick the shield. MACO shield is tougher since it reduces all damage types instead of just plasma, plus it gives you an energy bonus. Omega on its own isn't quite as good, but gives you even more speed, better regeneration, and the 3-piece gives you the Gravitic Anchor which can make alpha strikes just a little nastier. So MACO shield gives you extra defense, and Omega shield to put absolutely everything into offense.
On escorts, I tend to run the full Borg set. Reason being: gives you the hull repair proc (always useful), the shield regen proc (not as useful, but still has it's uses), and the assimilated tractor beam, which despite everyone saying it's horrible, the only weakness is the long CD. But it can immobilize your target almost completely, even with no skills specced towards it, AND it's a drain. A rather effective one at that. Add on to that the +5 power to subsystems, it works very well.
But if it's Omega vs MACO, basically what was said before. MACO for living a little longer, Omega for hit and run.
Use MACO or Elite Fleet Shields + (Borg Deflector and engines or KHG Engines and MACO Deflector (2nd option only if you are using MACO shields)). Never use Omega Shields only engines and Deflector and only if you have at least 6 in flow capacitors skill and at least one flow capcitor console and only use omega in PvP (the accuracy bonus is basically nothing anyway).
Edit: Elite Fleet Shields are better in PvP I would have to say (even though I use MACO because I feel like it (the best reason ever)), and MACO for borg and either for anything else (beware you will want to choose the Elite Fleet Shield type dependent on the energy type the other person is using if you can't afford both Elite Fleet Shields (and the energy types vary to much) then just use MACO Shields.
Right now, for lack of other options since I don't have the dilitihium or points to craft them yet, I'm running a full Jem XI set with polaron weapons.
It's decent, but not great. I say that only because I'm curious what weapons I should invest in until such a time that I can get all antiprot to go with the set I'm building from your advice.
Disruptor. They are moderately cheap on the exchange (can get mk XII purples for 1-1.8 mil depending on modifiers, can get mk XI purples for 750k or less, again depending on modifiers, my recommendation stick to mk XI blues (usually 120-150k on the exchange) with [crtd] [crth] as your mods, never fails), and the disruptor breach is infinitely useful in PvE and still quite nasty in PvP.
Of course you can go the blatantly cruel route and get Polarized Disruptors, adding on a polaron proc to your disruptor breach, and then enjoy the carnage. That will probably be enough to get you either 1) addicted to disruptors, like me XD, or 2) tide you over until you can get your AP weapons.