Depends on what you're looking for.
You can check EDDB.io.
This page allows you to search for modules and tells you where the nearest one is.
You can see from
that example, there isn't a single 4A power plant outside the bubble.
If you have the cash to tie up in module inventory, you can buy modules and store them before you leave, then have them shipped to Colonia after you arrive.
Or you can pre-build the ship you want and have the whole ship transferred out. That can get expensive though.
I took my Anadonda to Colonia to make the trip faster and then transferred my Courier out so I has something small and fast to fly around in.
I tried to re-fit the Anaconda but just couldn't find the modules to improve my shields, thrusters, etc...