This is my current python mission/trader build.
http://coriolis.io/outfit/python/07...t292f.Iw18eQ==.EwBj5BGae84kA===?bn=Python AMC
Notes: 1) currently class D6 shield, this should be either a Bi-weave C6 or a full C6, but I ran out of cash due to upgrading the thrusters and the distributor simultaneously. Note that the Bi-weave is only as strong as the class D although the faster regen is nice.
2) 2x D2 hull package gives more reinforce than 1x D3 for the same weight, if you don't need the other slot for anything else, which right now I don't.
I think I prefer the burst lasers to beam - power requirement is about the same but T load is lower - and with the recently fitted A class distributor, I can fire the bursts long enough with 4 pips on weapons to get the temperature warning. The bursts take shields down nicely and the 2 multi-cannons are nice for chewing up hulls at close range, then while they reload I use the lasers again
If doing a lot of cargo runs, you can swap out the class 6 shield for an A5, and gain more cargo space, also add cargo to the class 3 slots. For doing more varied missions, I would switch to a single hull boost and put an interdictor on the other 3-slot, but currently I've mostly been doing delivery missions, smuggling and cargo when there were no good missions. Equipping the Python to fight well is expensive, and as yet I haven't quite got it how I want it. Once the shield is back up to spec, I'll be doing some combat missions. Another point would be to add a KWS if bounty hunting, in place of one of the shield boosters. Going up to an A6 shield would mean dropping one of the boosters or going up a stage on power plant - and the B7 power plant is heavy, while the A7 costs almost as much as the ship. As far as I can tell, the only time you might need the A7 power plant is if you went for an A6 Prismatic shield - I can't really see how to use that much power otherwise.
BTW, those prices are correct: if you go to one of Li Yong-Rui's systems, there's a 15% discount on ships and modules.