I agree that PPSM is more likely for #250.
Ka-Zar will in all likelyhood be Masterworked in 2012.
Spider-Woman will be the first female Masterwork, but needs to wait until more Masterworks near the 80's.
Moon Knight and Alpha Flight will be released near the time of Spider-Woman, thus begins the "true start" of 80's Masterworks.
New Mutants will be after the previous three titles mentioned. Hello 80's!

The contenders for #200:
1. Luke Cage - my pick
2. Ghost Rider (Blaze)- has the sure edge for "monster" over Man-Thing (2 movies > 1 crappy, crappy, crappy direct DVD)
3. MTIO- not significant enough since MTU is already Masterworked
4. Man-Thing- (see #2)