The trouble with Target Lock is that you need to still fire all your weapons at once, so therefore you designate all your targets and then fire all your guns. You can't shoot one set of weapons before deciding where the other set of weapons are going to shoot.
I think Farsight bombs can be kitted out to engage two targets effectively at the same time and can tag a third (without destroying it), but no more than that. Since Farsight comes with a Plasma Rifle, one of those targets is heavy infantry by default. So, you can do either Heavy Infantry/Vehicles (with Fusion Blasters and Missile Pods scattered about) OR Heavy Infantry/Light Infantry (with a nasty selection of flamers and burst cannons there, as well).
What you could consider is this:
Farsight
3 Suits w/Dual Plasma, Target Locks
3 Suits w/Dual Fusion, Target Locks
1 Suit w/C&C Node, Sensor Suite, Flamer, Drone Controller
6 Gun Drones
4 Shield Drones (optional)
This is going to cost you a LOT of points, but when you drop, you'll get:
14 TL Plasma Shots (assuming rapid fire range)
6 TL Melta Shots
12 TL Pulse Shots (at bodyguard BS)
All of it ignores cover. Can shoot at up to 3 targets. It has 24 wounds or more, with the option for a fair amount of invul saves.