The January 2000 issue of Loaded magazine (out now in the UK) has 100 different front covers (special promotion for the Millennium), one of which features Monkey as the cover star! (Loaded ran a one page article on Monkey around the time it was aired on Bravo satellite TV channel in the UK).
Monkey is on cover number 83 - a quick glance down the sides of the magazines should help with the search. In each magazine, there's a fold-out poster featuring all the covers, plus an article listing the covers and brief information about each. Other covers available include Rod Hull and Emu, Peter Sellers, Begbie from Trainspotting, Basil Brush, Trigger from Only Fools and Horses.
Monkey fan Nikki Brown rang Loaded magazine to see if it's possible to get this Monkey cover from them by mail order. Unfortunately, it's not - they can't sell you a specific cover. Nikki also found out the following information from them:
Warren Pilkington's managed to get a copy of Loaded with the Monkey cover, and you can see it in all its glory here - click on the picture below to see a larger version of it.
1) The caption in the top left of the magazine: "For immortals who should know tripitaka" (each cover has its own saying in the top left relating to the cover image - e.g. "for men who should know better")
2) Monkey's holding the 'O' from Monkey in his left hand :)