Right now I'm a Human Explorer, but due to a lot of energy and exp boost from being a human I have been speed ranking lately. I want to start slow ranking as well as PvP. I already know I want to be a Konqul but I am not sure which profession would be best suited for a PvPer rank 150.
All suggestions appreciated.

You'll want to be a builder of fixer.
Guns cost a lot to keep - builder makes it more affordable.
Fixer gives more hull. More hull = more effective defence (you can take more hits).

Thanks for the advise Spyder

Excavator is also a valid choice. More art's=>More prisoners, ship-bots=> more powerful ship

I am debating whether choose builder or fixer.
Builder:
+: I will save a lot of credits from upkeep all of the guns.
-: Not a bonus towards PvPing, more like a long term kind of thing.

Fixer:
+: I will be harder to take down in PvP.
-: I would have to rely on repairing my ship whenever I don't have Repair Nanodrones which can have a big impact on my credits.

It already takes about 17M to repair my ship.

AARRGGGG...!!!!!

Builder helps more if you are doing passive stuff like missions. Fixer helps more if you NPC a lot, to reduce repair frequency (as opposed to cost). Either will help you at your level, there is a point where you cap at 200m repairs and fixer wins out if you npc a lot.

Cool, I never knew that repair cost caps. This definitely makes me go for fixer, plus I am planning on doing NPCs and PvP. Thanks a lot guys.
You were really helpful.

yep, ship repair cost caps at 200M

repair cost = (current upkeep / 6) * % of hull damaged

if your hull is down to 10%... that's 90% damaged...
if your hull is down to 0% (disabled)... that's 100% damaged...

if you are a builder... current upkeep = 0.5 * unmodified upkeep * 0.95ⁿ
if you are not a builder... current upkeep = unmodified upkeep * 0.95ⁿ

0.95ⁿ = 0.95 ^ # of dark assemblybots installed

fixer only gives you +50% hull (you can get a nice cumulative hull bonus going Lazuli Fixer with nanite swarm)
Yes, if you are NPC'ing a lot, fixer would be cheaper because of reduced # of repairs... (though the # needed to make fixer the cheapest option increases as upkeep increases)
if you are not NPC'ing enough to pay half of your upkeep cost in repairs, then you'd probably do best going builder...

Well I am looking at it from high rank point of view, heavy npcing, which means for me ~100 repairs a day = 20b, compared to the highest upkeep I had at rank 1700 which was 6.5b (note ppl are around 18-20b with all that fancy crap on ... I am not a completionist anymore I don't see the benefit for that much cost). So, builder saves me about 3b-4b , while fixer saves me about 25% of the total repairs which is ~5b , note this is VERY heavy npcing and that was at about 33k hull (with fixer included). But the other benefit of more hull was less repair downtime, I was tanking for 4m out of the 5m timer, so I was at 80% of the time fighting stuff and not waiting, meaning I could grind more terraformers and what not. In your case I would compare your repairs per day on average to your upkeep, and plan accordingly. Note that when you are not capped on repairs, builder also saves repair cost, but at high ranks when you got 200m repair cost, most likely builder will not save you on repairs.

I am rank 214 and do alot of NCPing. I am currently Aerlen Fixer. What would impact be on me if I went Lazuli Fixer?

You'd have more hull and less defence.

Thanks... doesn't seem the best idea for me then

The Lazuli/Fixer boosts multiply, so if you have great hull and mediocre defence it's amazing. The potential of it is alot better than Aerlen Fixer.