1. The most important part of escorting is scouting (one trade lane) ahead of the transport. Basically you can do this in a starflea.
2. If you're in a hurry and have to dispose of the pirate sitting on a lane, you can counter anything up to a gunboat in a hf/vhf quite tidily. In the worst case you would need 2 moderately skilled fighter/bomber pilots to down a gunboat.
Anything bigger than a gb can't attack a transport anyway.
3. You're a merc firm. Probably based somewhere, but that base doesn't really belong to you, so... Why would anyone want to "invade" you? I just don't understand why you would need cruisers at all... Actually I don't understand why you would need anything bigger than a bomber. Okay, a few gb's would be okay, and you can use Ahoudori for that. You can do the job just fine with civilian ships. Would be wise asking for factionised guns though.
Just my 2 cents.
EDIT: Oh, sorry, didn't really read that part about "getting dirty", hehe.
So my comment is obviously relevant only to the escorting part of your idea.
But I still think there's no need for any cruisers. If you want to collect a bounty on a cap ship, all you need is a bomber swarm:P
