Can I suggest that you are doing this all wrong...
Why is everyone trucking that heavy load back to the bubble when there are stations that offer all that you need right next door to the target area?
By not taking the goods with you, you reduce travel time, extend jump distance, reduce number of jumps and annoy anyone who interdicts you as you have no cargo.
Of course, I may well be teaching you all to suck eggs here, if so, my sincere apologises.
There are a couple of ways of doing this.
One, is to load up your preferred ship with fuel tanks and jump to Sothis. Convert these to cargo racks and start filling your boots. Once your rack is full, pop over to ceos and sell everything on the black market. Change your cargo racks back over to fuel tanks and then start jumping to your bubble based party station with questionable morals. Sell the fuel tanks for cargo, by what you need and then poodle around, fulfilling contracts.
The upgrade to this is to take a heavy combat orientated python, clipper, anaconda or asp with short range of jumps due to large shields, weapons, and other toys and leave it at sothis. At your bubble based emporium, you will store your python or asp with cargo space for all your cargo needs, along with weapons, shields etc.
To shuttle between the two, this is where your light as a feather, faster than lightening, jump range of the gods race ship comes into play. Zoom...
The only annoyance is getting back to the bubble, the first time you drop off your ship at sothis. Your only option is an e grade t-6 with lots of fuel tanks. That's 50 minutes and 45 tedious jumps, but once done, you are set up for a much easier life.
Well, this is working for me. Your results may very and come with no explicit or implied guarantee.