Yeah, probably should have written one up already. I'll put in the one for my character. As for the questions, yes you can use C3 equipped battlemechs, as long as you make appropriate space. Just remember that for anyone else to share your targetting data, they have to have a 'mech with a C3 slaved unit as well.
Also, I guess i'll take up the unit commander position. I'll need a couple folks for company commands. So far the unit will be a reinforced battalion, with a company of armor and aerospace assets, so i'll need 4 company commanders (which will be Captain, Major, or Lieutenant Colonel for mercenary ranks), plus a fifth if we need one. Like I said, a mix of the classes would be best, and any tankers and aerojocks would be great to have as well. Otherwise i'll just fill in the unit with NPCs to round things out.
Name: Jack Stryker
Unit: Stryker's Strikers
History: Jack was born to a moderately wealthy family on the world of Kittery, where he was brought up in a rather luxurious life. It was not until his eighteenth birthday that he left his homeworld to join with the AFFS to fight during the waning years of the Third Succession War. Rising to the rank of Major, Jack was called away from his duty during the year of 3029 when his parents were killed in an industrial accident. Feeling that his career in the AFFS had come to a standstill after the Fourth Succession War ended, he took his inheritance and began putting together a mercenary unit. Over the twelve years since he has managed to build it from a mere company of battlemechs without so much as a single dropship, to a full reinforced battalion with Aerospace, artillery, and dropship support. Now he works to increase his unit's firepower and standing in the Inner Sphere, wanting to push the Strikers to a full Regiment in strength before his retirement.
As for Battlemech specifications, I prefer them to look something like this, to help keep information comparable, and for quick reference
Engine: 300 GM XL Fusion
Mass: 100 tons
Max Walk Speed: 32.4kph
Max Speed: 54kph
Jump Jets: Right Leg, Left Leg, Right Torso, Left Torso
Jump Range: 120m
Armor: 19 tons Standard
Heat Sinks: 31 Standard
--ER PPC [Right Arm, Left Arm]
--Medium Laser [Right Arm, Left Arm, Center Torso]
--LB 5-X AC [Right Torso] (2 tons ammunition: 20 Cluster Rounds, 20 Slugs)
--CASE [Right Torso]
Character pictures are not needed, but helpful.