Get the largest FSD. The A class FSD on the eagle will cost you 500k. with the advanced discovery scanner and the DSS, that total comes to 2.25 million. Get a cheap fuel scoop, it'll do the job. I'd suggest making 100k or so extra money, because that's all you'll need to get all this and cover the insurance, too. This build will take you virtually wherever you want--I'd suggest moving towards the center of the galaxy though. THe stars get too thin if you go rimward. There will be patches of sparse stars, but this build will see you through.
If you want to get a few extra ly out of it, downgrade everything you can--the thrusters, the power plant, the power distributor. Remember, every extra light year in range is more valuable than the one before it. Just remember you will might encounter pirates for those first few hundred light-years, but after that, all your only threat will be heat damage.
Adder would work fine as well.