I'll be happy to report on quality, but my planned use is purely as a transfer pump (from an aux tank to main).
I'm certainly no expert, but I suspect that the relief valve you see in the tutorial is intended to be a 'fuse' to protect against a total blockage between the pump & the bypass type regulator (not shown, but described in the tutorial). My understanding is that these pumps are positive displacement, like an oil pump in your engine. If flow stops completely, either something breaks or the pump stalls & burns up.
You need pressure regulated to the design point, because flow through the injectors will change radically if you vary pressure from 20-25 up to around 100psi. Dan's right about early automotive FI; as your tutorial describes, later versions put the bypass regulator in the tank, and even later (current) versions electronically regulate pump speed to control pressure.
To address Dan's comment about experimentation: Some would say that anyone who flies a homebuilt is nuts. After all, if you want to go over 180 kts, you can just buy a Piper Malibu. Avoids that fuelish idea of experimenting with an entire airplane just to save a little money.
Of course, that means that the Airflow Performance & Precision exp. fuel injection systems should be avoided, along with the aux pump that Van sells, since it isn't baptized with alphabet soup, either.
If Dan just means that you should use what others have already used successfully (a reasonable thought), then the Walbro, with any convenient automotive bypass type regulator and a check valve, would fit the bill. The stock engine pump needs the check valve in the supply line so it can draw fuel when the aux pump is not running.
A simpler setup would be FRANKH's pumps: 2 high(er) pressure Facet 'solid state' pumps in series to get around 20-25psi. The only problem is that they seem to be a bit hard to find. If you go all-electric, like he did, you can avoid future ethanol issues with the Lyc mechanical pump. Or, 2 Walbros (main & backup) with bypass regulator, but that means a return line to the supply tank, unless you really do want to get 'out there' with fuel system experimentation.
Charlie