SAPPHIRE: Cadre means we're going to have a large contingent of green troops in missions, as well as mandatory skill checks for LOCAL COs, (bureaucracy, admin, leadership, and small arms mostly) to generate VP while we "train" the kids. It's effectively a defensive campaign type, and while basic supplies are easier to acquire, our BSP support is going to be limited. Probably either a cakewalk (even with Clan OPFOR), or it totally blows up in our face as we fail all the skill checks. Not much in between. But it's close, and it's short, even if it doesn't pay well.
XIPHOS: If we don't want to fight the Clans, this is my preference. Long trip, but A-rated MOC opposition means that we're getting CapCon and FWL stuff, and we get to keep a fair amount of it. Honestly, give our Mech lineup, this is probably an automatic win, but it's a LOT of time sink due to travel time.
IRONSIDE: B rated Clans means mostly frontline Omnis, and veteran Clan means 2/3 pilots on average. This gives us good allies, at least, and it's House Command, which means that we're likely to have a full lance on most missions. Salvage is reasonable for a Clan contract, and BLC isn't great, but of the Clan offensive contracts I think it's the best BLC being offered. And, again, it's short, and it's close. Base pay is poor.
BALDUR: This is basically a frontline Clan Steel Viper force, it's got crappy BLC, poorly-equipped house troops helping us, and CSV go out of their way to *kill* mercs. I don't think the base pay helps if we aren't alive to spend it. Personally, pass.
SABER: This is actually kind of interesting. A D-rated Clan force is a 2nd line force with some Star League refits, which honestly puts them at probably about equal to our firepower. Salvage is, again, about all we can ask for on a Clan contract, and the BLC is lousy, but the base pay is reasonable. I also look at who's hiring us. This is the sort of "go capture Clan look and bootstrap a Periphery industrial program" mission that can actually have interesting objectives. The travel time isn't terrible, and it's not a long contract term. Of the Clan contract, this is by far the most interesting.
BOXER: Heavy defenses, and high-end Capellan troops with top-end gear. Salvage is the best available, and BLC is bordering on good, 13 weeks travel is right on the edge of what we're probably considering acceptable. The question is whether we're valuing Capellan salvage pre-Stealth Armor as all that great. The planet is functionally an industrial wasteland; it used to be the BattleTech equivalent of a 40k Forge World, so we'd have a lot of urban fighting, I think. Don't really know if we want to deal with that. IMO the cons kinda of outweigh the pros here. It's a doable contract, but I'm not thrilled about it.
Conclusion:
I think my preference would be for SABER, then IRONSIDE, the XIPHOS, in that order. SAPPHIRE if we really don't want to do more raiding contracts which, in fairness, I know that people were wanting something different this time around, but SAPPHRE is just as dependent on your abilities to pass skill checks as it is your ability to play tabletop BattleTech.