Hi mate, I think most people are torn the same as you before having it done, but the second you even see the first session finished there is not a doubt in your mind that you have made the right decision and I was 1000% happy that I went for it.
I think we worry about every possible thing when looking into smp, but the end of the day the only question you need to ask your self is do you want a hairline or not want a hairline?
You head looks very normal shape to me mate, I say just stick to a natural hairline and you will love it like everyone else that has it done.
And yes Skalp is the only place I would let touch my head, by far the best.
Keep us updated if you go for it.