*pokes head in...
Ok I've been slack myself but I expected something...
Anyways wombat, typically we do colabs via steam chat, using the roll20 site linked in the OP for making rolls when required.
However its entirely possible to use another format, say Pirate Pad, which we have used in the past, or even via PMs on the guild, actually the new guilds PM format is better suited to colabs than the more traditional pm system. that said your first bit doesn't require a colab to get moving,
You merely need to contrive a way for the doctor to secure your services to get him and his cargo from Coruscant (where you're starting apparently) to huttspace. Basically you can take the job and head off, then you'll need to colab the result which could depend on a number of factors like the rout you take to huttspace, the speed of your hyperdrive the luck of the dice and a number of other GM controlled variables that go on behind the scenes. Chances are you'll need to colab with Sarz sicne he's GMing the Republic side of things in the rp, once you get into huttspace there's a chance you might need to colab with myself since I GM the Syndicate, though there's a rather lower chance of that than collabing with Sarz.
Now with all that said, I'm going to break my RP silence wide open tomorrow and get a post done with at least one of my characters tomorrow night, come hell or high water.