Thank you for reading my questions. My bike has been sitting for <5 years and I want to get it (and me) back into shape.

I have a ~2000 Breezer Lightning I bought in college. I need to overhaul the drive train, I'm still on the first set of front and back rings. It is an 8x3 setup. I also need to get new Grip Shifts. My questions are:
1. I think I ned a H651 - 28T rear cassette, I"m going to the the CH HG71 chain as well. Is this a good choice?
2. Front chain rings, the big ring is printed Mega9 and the rings are stamped M9 N22, N32 and N44. I'm at a loss where to find replacement rings. I cant identify the exact model. Can someone suggest replacements?
3. I have not modified the bike in any way and again it has an 8 speed rear derailer and Grip Shift but my reading today says that Mega9 was for 9 speed derailers. Was is common or even okay to use an Mega 9 front rings with an 8 speed cassette? Will this cause chain problems?
4. Are Grip Shift 3.0 shifters most appropriate?

Thanks for your help.