J. E. Lee is well versed in his/her response to you. Although not easy, an abeyant title is more likely to be bestowed than a new one. This in itself carries prestige as a new title would have no history associated with it. In order for an abeyant title to be granted, the original title grant had to have had a Special Remainder clause. Simply put, this means that, in the absence of male heirs, females may inherit the title. This Special Remainder is granted much more frequently in modern times that in the past. A good example would be Earl Mountbatten of Burma. When his title was bestowed, it was clear that he would have no children other than his two daughters. The Special Remainder clause was attached to his title, allowing the current Countess Mountbatten of Burma to inherit the title. Some, however few, much older title carried the Special Remainder clause and are certainly worth investigating.
I would like to respectfully correct an err in J. E. Lee's response: One would NOT have to be a British Citizen, as there is no such distinction. We are considered British subjects (subjects of our Queen); the technicality that we are not citizens of our own land, has long been a hotly debated political issue.
One would, however, be required to be a "subject" of Her Majesty in order to recieve a title. The implication here, is that it would not appear correct for Elizabeth II to run around bestowing titles on those who were not under her command.
AND, United States of America law, constitutionally forbids American citizens from accepting foreign title. One could, however, relinguish American citizenship, as did Queen Noor of Jordan and Princess Grace of Monaco.
Much success to you in all your research!