Tires - 100/90-16 instead of 110/90-16???

[samato]

I read in another post that someone is considering using a 100/90-16 front tire instead of the factory spec of 110/90-16. Can anyone comment on this in terms of safety, performance, durability or any other issues this could cause. If this is a reasonable thing to do I'd be happy because I saw in a Chaparral Motorsports catalog the following prices for Kenda K671 Cruiser St Tires:

100/90-16 - $46.85
130/90-15 - $49.85

At the moment I really only need a rear tire but I'm worried about being able to find a matching front later plus unless I buy a Metzler ME77 for the rear it's not going to match my front anyway. I've heard that can be a bad thing but I have no experience of my own with this.

Basically, I'm looking for any advice as to what I should do. I know I need a rear tire right away (it's really worn) but I don't know anything else really. I'm planning on learning to do all my own basic maintenance on this bike but I really know almost nothing right now.

Thanks to anyone who can help.