Who still makes a supercharge kit?

[AstatenateZ]

I am looking to buy a like-new used kit.

From what I can tell Stillen still makes a kit (new) but I don’t want a Stillen kit as I’ve seen dyno sheets of them after being tuned and it’s not impressive (low - mid 400 whp) for a 7k new kit. So not looking for a used Stillen kit.

Trying to gather info as I plan to go SC soon! I saw GTM 1.5 kit that makes 500-550 WHP and that’s what I’m going for as I can see a 7A 370z safety running 500-550 WHP. But from what I saw GTM went out of business or no longer sales the kit new or offers warranty, correct?

So is there any other good / reliable kits I can buy used, that make 500-550 whp?
And what price should I look at spending on a good lightly used like new kit?

Who even makes a SC kit for our platform? Only GTM and Stillen. Please list all companies/ pricing for SC kit?

Thanks in advance!