Hi!
You don't need anything extra to run the OS .1.60! No pump and No regulator.
It will run just fine anyway you mount it, if you just run it on 5% nitro (no more is necessary) a OS 8 glow plug (or an Enya 3 plug) and a 500cc fueltank (preferable a Tettra Bubbleless) mounted correctly.
If you use an ordinary fueltank go with a "Uni-flow" set up for best results.

Some advise. I have flown for 31 years, and you have only flown 1 year and are already aiming for a 1:5 scale P:51 Mustang...that's no good ! You better try some other, smaller, faster low winged airplanes first so you get used to fast, maneuverable machines before you get that P-51 up.
P-51 one might be what many consider "the ultimate thing" but they are no good fliers compared to an ordinary low winged sports model.
It's also very dangerous to go to such powerful engine like the OS 1.60 when you are so inexperienced. I would go with some .40 size low wing models first and I recommend trying
Q-500 pylonracing if you want to become a good pilot, there you can find good R/C pilots and get lots of valuable information!
Regards!
Jan K