If you can really get an Amuse kit at that price, its hard to pass up.
Thing is, you want to do it 100% right, I would only do the kit if everything else exterior wise looks top notch. I don't recall in the previous posts if you mentioned being on stock or aftermarket wheels?
A kit like that deserves a great stance and top notch wheels to really get the full effect of the look.
If you already have money set aside to fix the rusting quater panel, and you got the wheels to set off the kit, I'd go Amuse.
Otherwise, I'd get the car back up to spec first, good luck!!