I have ordered A LOT of pretty big metal prints.
However, I have only used two companies for these orders; AdoramaPix and Fine Art America. . Of these two, each is better at something different.
AdoramaPix is good because they offer several different finish options - glossy, satin (matte), glossy silver, and silver satin. . They used to only have sizes up to 30" by 40", but now they also offer large sizes - up to 40" by 60".
Fine Art America is good because they will make metal prints in any aspect ratio. . So if you crop an image to non-standard proportions, they will make the metal print to those proportions.
The problem with FAA is that they only offer a glossy finish. . This is a big problem for me because so much of what I shoot is nature, which seldom looks good with a glossy finish. . But it looks like you shoot motorsports, which subject matter lends itself quite well to glossy, and that's probably what you'd pick, anyway.
I don't know if either of these companies is "the best", because I haven't used any others. . But if you want advice from someone who has actually ordered a lot of pretty big metal prints from the companies they recommend, then my info may prove helpful. . I've ordered over two dozen metal prints from each of these companies that are sized at 24" by 36" or larger, and never had a problem. . Plus countless smaller metal prints from AdoramaPix, and never had a problem with any of them, either.
"Your" and "you're" are different words with completely different meanings - please use the correct one.
"They're", "their", and "there" are different words with completely different meanings - please use the correct one.
"Fare" and "fair" are different words with completely different meanings - please use the correct one. The proper expression is "moot point", NOT "mute point".