The Galaxy-X makes a sweet Aux2batt build with an abundance of engineering slots. What Aux2batt does is it will transfer all of your Aux power equally to Weapons, shields and engines. I had an Aux2batt Dreadnought spring '12 but currently running a Fleet Avenger. The main selling point of Aux2batt is when you slot 3 purple Technician doffs you will get a cooldown reduction of your bridge officer abilities. So your EPTX, DEM3, RSP, TT, BFAW2, APB1 etc will all be on global CD if cycled properly. (and that takes practice)

This is what I used to run in my Aux2batt Galaxy-X:

BFAW, APB1(for PvP APD1) TT EPTS, AUX2BATT, RSP2, DEM3 ET1, AUX2BATT, EPTW3HE1, TSS2

3 TECHNICIAN DOFFS 1 CONN OFFICER to reduce TT CD and boost attack patterns 1 warp core engineer to boost power levels

When possible I would get the Borg deflector and engines Mk XII. ELITE FLEET SHIELDS RESILIENT ResB. Bc you lose some healing with the Aux2batt the borg set helps with its hull proc. You should be able to tank with shield power well over 100. Plus with extra in engines you turn better. I used to make the big girl dance lol.

Also I know it's very expensive but Plasmonic leech is key now a days. It used to be a Klingon only console but is now available on the exchange. The Maco shields don't work properly with the leech so don't bother with both.

Also go for the borg cutting beam and assimilated console. It's a nice 2 piece bonus. I would stick with phasers since you have the phaser Lance.

Carry 2 stacks of Aux batteries. When you need to heal you hit your Aux battery then activate your HE and TSS2, then go for your abilities then hit Aux2batt. 1 battery to affect all your systems.

1 more thing. Jump console is nice since it will put you in a perfect firing position to use the Lance and it has the same CD.

If you need more help hit me up in game anytime @edalgo.

GL