Extreme variety is extremely hard to do without boosting. While it is possible (I did it once), a lot of the bonuses you have little to no control over (double/triple escapes, close call) you just have to get really, really lucky.
Hidden
Incognito,
Uhh...whatever the not max kill bonus is named,
Poison,
Escape,
Drop Kill,
Acrobatic,
Mid-air,
Savior,
Poacher
These bonuses you should be able to get pretty easily in any MP game. If you try a little bit harder/get lucky you can get Grounded, Double Escape and Triple escape. If you have to, you can boost but it requires at least 3 people. Good luck.