Doing that peak on the dyno sounds doable. Don't plan on driving around with that power without frequent stops to the gas station.
The fuel support needed for big power is a gas guzzler. My car gets about 4 mpg but I do make a lot more power - I'm just giving you an example. When I was making about 690 rwhp on the street on 91 gas, I was getting about 10 mpg through #83 injectors a big pump, and -8 lines... now I use #120's to support my power.
If you don't take the time and money to do your suspension right - you could be asking for trouble with 700 as well. Plenty of streetfire videos showing what happens when you punch 700 rwhp on a mustang without a stout suspension to back it up.
I'm not trying to dis your build at all - just trying to help you is all and give you stuff to consider. Making peak HP on a dyno is pretty easy. I try to tell everyone to forget all about dyno numbers and just try to make your car as 'fast' as possible with the power you have.
At the end of the day, no one cares about dyno numbers - it's all about who can get from A to B the fastest...