Here's my take on their options...
Planet Eclipse has a ton of teams right now. They're good people, make great guns and have their hands in alot of pots. With that being said, it's hard to imagine PE footing the bill for another international team, especially one as strong as RL. Legion has an amazing base, but I don't believe that Eclipse could handle that many teams for much longer with the way the market is and would be a great challange for the company to keep up with the team, PL markers, gear, etc.
Seeing as KEE is a major sponsor, it would make sense for an Angel deal to go through. With Angel rebuilding their base, it would be a good step for them to go back to their roots. Losing Rage is a big loss to the company for sure. Not many Pro teams have been shooting Angel's in the past few years, the line has pretty much died out when only years ago there was nothing better, and Dynasty and everyone else shot an Angel.
With that in mind, if the guns would hold up, RL could do extremely well with the Angel markers. A RL PL A1 would make alot of sense, but then the capacity at which Angel is opperating at the moment doesn't allow for too much play in that direction, so it could be very unlikely to see an RL Angel for quite sometime even if they did sign.
Macdev would make a great sponsor, but they aren't as big as the companies RL would need. I don't believe with the recent signing with Rage that Macdev could give Legion what they really needed. It seems like a distant option, but probably the most reasonable.
I wouldn't understand why SP wouldn't resign with the team. My best guess is they will sign a new contract or at least an extention. Has there been one word of SP NOT signing RL? I haven't heard any...
Dye would be an excellent choice. With RL shooting DM's, Dye could become a front runner in sales with the two largest teams on the NXL circuit under their umbrella. It would also cut out alot of competition between them and PE, and give RL a great opportunity to expand it's reach stateside. An RL DM8 would be nasty, and probably outsell their other PL DM's. If I were RL, I'd consider that my best option. I don't believe they've ever shot Dye guns, or their take on the markers, but it could be an amazing duo.
As for the rest, there isn't much else left out there. With a team like RL, I'd suppose a power house company would pick them up, or something to happen through KEE. SP is probably the best option as of now, but if that isn't a possibility, then Angel would make for a good deal. In the long run RL has many options out there, I just think the marjority of the market wouldn't be able to properly meet their needs.