I am the proud owner of a Cary SLP 90 with phono. I'm looking for a suitable M.C. cartridge to be used with this pré-amp in combination with my Project 6.9. Some tips please?
Jernst: I heard on yr TT & liked, Benz Glider, Clearaudio (the $ c.500 model), V D Hul (again around $4-500).

Pls excuse my imprecision, I don't remember the models offhand.

I just upgraded to a Sumiko Celebration with great results. Used a Benz 0.4 before.
the ortfon mc30IIsuper for $500 from needledoctor is a fine authoritative cartridge at the price. i would not hesitate to go for it if i didnt have about 9 carts.
That's a difficult question given the fact that you do not state the type(s) of music you listen nor how many albums you have. Please be specific next time.

A good starting point in moving magnets would be the Van Alstine modified Longhorn Grado ( or the Shure V15 Type V.

For high output MC starters I would definitely pick the Sumiko Blue Point (not a good tracker, but great spatial imaging and musicality) or the Ortofon X3 or X5 (good tracking, good dynamics, accurate). Dynavector would be a good choice in the same price range, too. You can find a brand new X5 here in the classifieds for $110. That's grey market (Hong Kong), but it would definitely be the best performance dollar for dollar (lists for $325) you could get right now.

I'm not going to get in the low output MC arena. Too complicated and, IMHO, not really worth the extra trouble and money.