As you have indicated there are those who consider it forbidden for people who have been guilty of fornication to marry each other, even if they have repented. However, there is a second opinion; this is the view of those who hold that it is permissible, as long as they have sincerely repented of their sins.

The first group base themselves on the texts which establish clearly abhorrent nature of zina; and bar people who have committed such sins from marrying each other as a penalty for their sin. They say, it is thus analogous to depriving a son who kills his father from inheriting him as a penalty.

The second group however base themselves on the texts which state that all sins can be forgiven once a person has repented.  The Prophet, peace be upon him, said, “One who has repented of a sin is like one who never sinned at all!”

The last group also point out to the fact that since they are inclined towards each other in the first place, there is a better chance of protecting each other, which is one of the primary intent of marriage as an institution.

In conclusion: It is permissible for you to follow the second view as long as you have repented of your sins, and you are determined to lead a clean Islamic life. May Allah guard us all against the evil inclinations of our carnal souls and bestow on us modesty, chastity and sincere faith-aameen.