I am sorry but I don't think that the Rarity of Lincoln Cents are recorded anywhere (and PCGS and NGC Pop numbers should not be used as these are only for certified and graded coins by these two top tier Grading Services), at least that I know of! The reason is, because there are so many Double Die specimens still out there in Albums and hoards in someone's Collection. The three books below are the ones that I would recommend but the first one will not have anything on the 1994 Double Coumn Varieties, I believe the same is true for the second one but the last one by Billy Crawford should have. Everyone is hoping that Wexler and Flynn will publish some updates sometime in the future.
The Lincoln Cent Doubled Die by John A. Wexler. This classic 1984 book is still used by many today. The 226 pages (5.5 x 8.5 inches) feature over 200 Lincoln cent doubled die varieties known at that time profusely illustrated with over 550 photos.
The Authoritative Reference on Lincoln Cents by John A. Wexler and Kevin Flynn. Published in 1996 this 384 page book won the 1996 Numismatic Literary Guild award for "Best U.S. Coin Book" in 1996. Packed with historical information on the Lincoln cent series the book also features the top doubled dies, RPMs, and OMMs for the series as listed in the Wexler Die Variety Files, along with in depth looks at the 1958 and 1969-S doubled dies.
A Detailed Analysis of Lincoln Cent Varieties 1959 - Present by Billy G. Crawford. This new (2009) CD book covers the die varieties on the Lincoln Memorial cent series as listed in the files of noted die variety specialist Billy G. Crawford. The varieties in this massive 712 page reference are profusely illustrated with photos of the variety and the key die markers that will assist in the identification of that variety.
Frank