A Major Story/Event ends with The FF Sacrificing themselves to save the universe, a holowill is left behind Reed wants the FF to continue, but 4 may not suffice, he has Programmed Herbie to round up a new team to be the worlds premier super-team they are....
The Fantastic Force
Dr. Bruce Banner
Now that Banner can no longer can turn into the Hulk he is the only Super-Genius Reed feels is stable enough to involve in this endeavor, he's the smart guy that every super-team needs.
Nova
The Fantastic Four often clashed with cosmic threats, and they always had to learn on the fly, a team that will be facing cosmic threats should have someone who knows what they're dealing with, after hearing of Nova's exploits since Annihilation Reed has developed great respect for Richie, so he picks him. Nova flattered to even be asked, accepts the offer.
Ian McNee
The Fantastic Four often came up against threats of Mystic origin, and Reed will be the first one to admit he doesn't understand magic, he consulted Dr. Strange, and Strange suggested this sorceror for his team, McNee, desperate for upstage Strange in anyway accepts the offer.
Ant-Man
In any ordinary circumstances Eric O'Grady would never never never never make it on Reed's list, but here's the thing, noone upgraded Herbie's files with Scott Lang's death, so as far as Herbie's concerned O'Grady is Lang, Eric accepts cause he's a whore, now he has to stay in costume whenever Herbie's around or he'll get thrown out of the building like Jazz form Fresh Prince
Spider-Woman
Impressed with her work with the Avengers and S.W.O.R.D., her status was a hero and spy makes her an advantages get for getting out of sticky situations
Beta Ray Bill
With Thing Dead, Hulk, gone, and Thor too important a figure to be associated with a team, Reed felt they needed a strong arm, his mystic and cosmic ties factored into his inclusion largely
Cloak & Dagger
Reed wouldn't admit it but he's always kept an eye on the young super-humans of the world, looking to find those that will be the A-list of the future, these two have been at the top of Reeds list as future greats for a long time, now he's tossing them into the frying pan to jump-start their status.
Iron Fist
*work in progress will finish later*