I have the mugen replica, you're probably looking at the same groupbuy I was pondering for almost two months.

I was seriously considering the Si one, but it's a little too conservative.

If you do get the mugen one, it's made of plastic, so it won't crack or sag like the fiberglass or urethane ones. It fits ok with the brackets that come with it, but you may want to relocate where the brackets attach. If you do you'll have to do some custom fabrication, like bending the brackets or even making your own. I'm happy with mine, I'll post pics when I'm not so lazy.