Parts Wanted Looking for parts or info about them! Gas tank and exhaust specifically.

[Engage]

Hi, I have read the older threads about 2nd gen gas tanks and this is really my number one mod for my new to me 2020. I have seen a German 6.4 gal, LS3K, and a "Mars" 6.6gal mentioned. In a perfect world I would like the biggest. That said so far "I think" I successfully emailed the German company and have received no answer. Do the others exist? Number 2 mod is I am also looking for a V&H CS One exhaust mostly because I like the looks of it. I saw a new set of CS one slip ons for a 2nd gen Hayabusa and thought about Frankensteining a system by using a Akro mid if the diameters lined up. Thanks for any info and leads. I have yet to get any saddle time on my new to me bike as the former owner signed the title incorrectly and I have to wait for the new one to arrive.