Sorry to bump this but as a "noob" who picked up on this area as a location to improve Federal rep, thought I'd post from my experience.
First off, if you're travelling to Ceos/Sothis it's a long way from anywhere else involving travel through multiple anarchic systems with sweet nothing. A fuel scoop is essential especially if you are in a lower spec craft, otherwise at best you will be making your first acquaintance with the Fuel Rats, at worst you will be contemplating self destruct and (possibly) your first rebuy

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Once in system from what I can see there is one station in Ceos and two in Sothis. They all seem to offer multiple BBS missions so these really stack up. Even at my lower level I'm making around 350k per round trip and I exchanged my passenger cabin for a freight unit as many of the missions require hauling merchandise or offer resources as a reward/bonus.
The downside is that having done three or four round trips while my cash is rising the Federal rep so far isn't. Need to work on that. Also spending too much time trundling between the same two systems is going to get tedious after a while even with the eye on the prize, so to speak. Also the shipyards at the two main stations don't seem overly well stocked with better class modules.