Of all the ARC-170 pilots, Shara Bey is clearly the support. Although you'll have to build your squad around her, she provides a good ability to share target locks.
Although the range is limited, a Weapons Engineer can provide flexibility, allowing for friendly ships to modify shots and/or launch ordnance at a target.
I've run her next to Nera Dantels on occasion with excellent results. It's overall a fun build.