Alright a few things.
First - Don't tighten the filter on with a wrench. Severely overtightening the filter may cause it to leak which is a huge pain in the ass (I hate it when my machines leak oil anywhere). On the other hand, if you keep it too loose, it may leak oil also--I'll get to how to get the right torque in a second. You want to remember to oil the seal on the filter with fresh oil (THIS IS REALLY IMPORTANT) it will help it go on real easy with the right seal--an unoiled seal may tear from friction. As soon as the seal contacts the landing...mark a spot on the filter and do one more complete rotation of tightening BY HAND back to that point, and the seal should be just the right torque. It's pretty hard to go wrong in overtightening as long as you only do it as tight as your hand can make it...
Second - As far as the right oil goes. Go with a synthetic. It is really worth the money. I have done a lot of research into different types of oils and how engines wear (as I rebuilt the turbo motor on my Eagle Talon TSi). Engines using synthetic oil have much less overall engine wear especially in the valvetrain compared to dino oil (real important in high revving or turbo applications). As far as oil goes you want like a 10w40 synthetic. Mobil 1 is really good stuff, I swear by it. As long as you make sure you get "Mobil 1 Motorcycle Oil" you should have no clutch slip problems. They designed the oil minus the friction modifiers that cause clutch slippage in wet clutch systems because they took into account most motorcycles have wet clutches.
Last - Filter. Go with OEM and you can't go wrong. On my cars I use Mobil 1 Performance filters, but just call that brand loyalty. I'm not sure if they make them for motorcycles but on my Ninja I just use Kawi Filters.
Good luck and rev the hell outta it! You'll know you got the best protection possible in the crank case!
Phil
1998 Kawasaki ZX6R Ninja
Let the good times roll!