Like many other explorers who are veterans of the 1.4 fiasco, I made sure I was nice and safe back in the Bubble when the update landed. FD have had too many updates in the past where explorers were left in the lurch with a game-killing bug introduced with an update.
For the record, only Small ships get a free (loaned) Supercruise Assist module added to the off-the-shelf model when bought; they also get the new Advanced Docking Computer. Medium and Large ships only get the Advanced Docking Computer installed as standard in their single extra slot.
The space station where I've got all my ships stored is an Agricultural station and didn't have any Supercruise Assist modules for sale. So I bought a bunch of Sidewinders and Eagles, and stripped them of their loaned components before reselling them. That gave me a stash of the new modules I could fit into all my stored ships. So I don't know how much a normal, non-loaned Supercruise Assist module costs, or what kind of station sells them (I didn't see any for sale at an Industrial station I visited, either, so presumably they're High Tech gear).
I've now headed off on my next months-long voyage, so I hope I learn to like Supercruise Assist in my AspX, because I'm stuck with it now.