Are they reliable or could they be messed up? Thinking about purchasing one
They are pretty reliable and there isnt much that can go bad. Post the ad and we can comment on it.
The supercharger itself is the most expensive wear item but even they can be had for 200 dollars or less if you find the right deal. That being said, unless seriously abused they are known to last 100,000+ miles easily. Definitely a fun, reliable setup for these cars.
"In Oldskool we trust"
Those are ok..but you are missing some parts for the full kit. Depending on what you do for a tune the injectors may not work for you. The tb will not work for you. He is a very good seller though. Maybe contact him through cobaltss.net. His name on there is mongorat. He will likely be able to customize the kit for you for the parts you need.