Gauge

dont know about oil but you woulnt need any higher than 100 for fuel i am also geting a fuel guage soon.

The 100psi is fine as well.

100psi is fine for each. For fuel pressure, 15psi is for carb'd applications and higher ones are for EFI. Make sure if you get one that it's a full sweep, or it will be pretty useless. You're only getting two? Just my $.02, but you'd save a load of money and have what's more important if you got a water temp and oil press for inside and then put your fuel press under the hood. Interior mount fuel press gauges are electric and pretty expensive, while an underhood mount is mechanical and relatively cheap. You could probably get all three for the same price as the two you asked about.

100 and 100