I have a ton of posts about this years ago and did just a ton of research in how to make it work in NCAA 14 and here are your options:
1) Use Air Force - It gets you closest to mid-90s Nebraska in terms of inside/outside zone run and option while still having enough pass concepts to not be screwed when playing online.
2) Custom playbook
#2 is obviously the best option, but you really need to be careful with your formations and concepts because in order to get everything you need, your playbook is going to be at/near the maximums.
The formations you need are:
Ace Big
Ace Big Twins
Ace Slot/Normal
Ace Y Trips
Ace Trips (not necessary, but it is so much easier to recruit WR than TE and you *need* a 3x1 closed formation like this or Big Twins)
I Slot
I Normal
I Twins
I Twins Flex (yes, you need both*)
I Y Trips
I Tight
I Twin TE (can be omitted)
Power I
Maryland I Tight/Heavy
Flexbone Normal
Shotgun Spread (if you have a really athletic QB) or Spread Flex (if your HB is your primary ball carrier)
Your concepts in every formation essentially need to be dive/inside zone, stretch/outside zone, toss, FB dive, triple option, speed/load option. Nebraska rarely/never ran actual triple option, but there is just no way to replicate Nebraska's option game in NCAA without using triple option. It sucks, but it is what it is. Especially with speed/load option being kinda broken.
Now the reason you need both I Twins and Twins Flex is because the toss play that is in Twins Flex is, for lack of a better word, epic. The ability to flip it and the effectiveness of the block, especially if you motion the outside (off) WR to crack block will make it a 8+ YPC play for you. 41/49 Toss was THE play that made Nebraska go in the 90s and so you need to make it work in NCAA 14 to replicate the offense properly. Unfortunately, most toss plays in the game don't work. The best are the tosses in I Twins Flex, I Y Trips and I Tight.
All of that said, there is a little wiggle room with formations depending on what you want to do. A lot of those one back formations Nebraska used in real life actually had the IB placed at 4 yards and utilized a wingback to run orbit motion as a pitch back for option. You can't use Ace to do that, so you need Flexbone. Flexbone has a few good formations you can make work to really implement a true wingback (late 80s and also late 90s/early 2000s Nebraska did this more than 1995).
In terms of pass concepts, basically what you want is a PA off your most used run concept (should be stretch/OZ), various sprintouts, and a quick passing game. If you intend to use this online, you might want to add a few more gun formations because too many people will just load the box on you and make passing out of it a tough situation. I'm the author of the Spread-I offense on Utopia which was essentially created to take this 1995 Nebraska offense and put it in the pistol/gun where it could actually be used online but I'll admit it is less fun than making the authentic under center zone power run offense work.
If you need any more help, let me know.