Encrypted Data Chips are traded at a vendor in DS9 for STF gear, including the Omega and MACO space and ground sets.
20 EDCs will get you 1 Special Reserve Mk X Requisition, which you can use to get one piece of any Mk X set (make sure you pick the right requisition though, there's one for each piece).
40 EDCs will get you 1 Special Reserve Mk XI Requisition.
You can also get Very Rare basic equipment in the Mk X and Mk XI range, usually tailored to fight the Borg. In particular, weapons come with the [Borg] modifier that causes additional damage to Borg targets.
OK Thanks! I just barely leveled up where I can now do The Borg stuff. and My Character is a KDF Officer!
You can join in the STF action by either running with a group of friends or fleet mates. The other way to join in is to click on the volunteer area from the mission window, from there click on quick play and que for the STF you want to play. Remember that there is a total of 6 normal STF's and 6 elite STF's. They are broken into space and ground missions.