To look at this more closely.
Outworlds Alliance: They build the Stinger, Wasp, Locust and later the Merlin(3010?). They border the Draconis Combine and Federated Suns, and are frequent targets of pirates. So, heavy on bugs with lots of salvage or purchase of units "maligned" by their neighbors. Blackjacks, Chargers, maybe a run of Valkyries(the FS make 130/year), Perhaps a few heavies(Thunderbolt, Warhammer, Archer, Marauder) from the TC in exchange for aerospace fighter trainers.
Taurian Concordat: They build the Stinger, Wasp, Locust, Commando, Griffin, Thunderbolt, Warhammer, Archer and Marauder. The Griffin line should, perhaps, be replaced by the Toro as it is a homebuilt Taurian mech with the same loadout as the Griffin. They also had the Hatchetman listed in the first Periphery book, it could be replaced by the Talos, another Taurian mech that had the same AC 10 as the Hatchetman, misreporting? Other than the purchase of a few assault mechs, Banshee(converted to the two PPC Marik version?) and anything else they can find, they don't need much more.
Magistracy of Canopus: They build 50 Stingers, Wasps, and Locusts and 10 Shadow Hawks. They border the Free Worlds League and Capellan Confederation. They become very friendly with the Duchy of Andurien around early 3000. They also have a 240 engine from the Manticore and a 225 engine from the Sabre ASF that they make. Their 3050 plus mechs were the Calliope(40 tons) and the Penthesilea(75 tons). Downgrade those designs and you get a Hermes II clone(Calliope) with a LL, SRM 4 and LRM 5 and a 3/5/3 Penthesilea with an AC 10, LL, PPC and 3 ML's. If you don't do that, you can buy from the Free Worlds which gives you access to over 20 designs. Most likely the Flea, Hermes II, Trebuchet, Quickdraw, Rifleman and maybe a Griffin or two.