Hyperspace Survey module MK3 gives you coordinates with 25k accuracy, MK II gives you 50k accuracy. It may not sound a lot more, but if you really use them for trading, every second will be valuable for increasing your profit. Having to fly 50k+ after each jump starts being annoying as hell.
There's no need to keep Survey Module equipped, since the coordinates expire every 30 days. As for other equipment, you don't need anything except a shield ( maybe not even that, if you rep your ship nicely ), so you'l have 1700 (or 1800) cargo.
JD IV's nice, but only if you fly with friends all of the time. Using it solo is game-breaker, since you have to wait 4x longer to charge your drive. It's more profitable batteries consumption-wise, but it's less profitable credits per minute-wise.
