Wow $4500US is still expensive, but I guess that may be the range for an S52. I've actually never priced out an s52 yet so I wouldn't know what they run here. If your getting a front tower strut brace ive heard that the aluminum ones are too soft and don't offer much support. From what people had said the steel ones are worth the added weight.
Those OEM ones are expensive! I think I had one of mine replaced and it was probably expensive too. I've never done my own wheel bearing change. I hear it's a PITA. Maybe next time my car needs one I'll attempt it.
I love the idea of supercharging as well. I love the idea of the added power available with the push of the pedal. If he a little worried about stop and go traffic but other then that it would be great. I think instead of a kit you could try sourcing parts peice by peice. Try to find a blower that would mount up. Maybe Downing Atlanta can give you a list of the parts that they used in the kit. I would assume it would be more expensive to do part by part but it may be a more successful option.