Where to buy Spike for the sump? turboing td42

Hi all, I've decided to bite the bullet and turbo after months of fretting. I have sourced everything I need to buy, only thing now is the oil return.

(I've done a search and couldn't come up with anything for my question)
I feel more confident spiking and tapping the sump, rather than welding (otherwise I would weld an AN nut on there).
I would prefer to do it myself for the experience. Obviously if I screw something up I am prepared for the cost haha.

Is there anywhere that I can buy a 14-16mm spike?
I don't mind paying money for it, since I will most likely do my dads TD later.

Thanks in advance.

when i turboed my old tb42e patrol i just drilled and tapped the hole and installed the fitting with a good coat of locktite hyrdraulic sealant and it never weeped a drop in the 5 years before i sold it.