A 451 is what has been sold since the 2007 model year and inported into the US since 2008 ,the ones that most folks in the us have. THe 450 is what most of the world had but didn't meet US standards and required modifications to bring into the US. Parts for one will not fit the other.
Since they are even different sizes, and the site doesn't specify, it is unclear if the parts and execessories will fit my car or not.
If you have purchased and are happy with parts from them, then post pics so we can see how they look.
You should also know if they realy want respect on this site, their are supporting partners, they get quite a bit of respects on here.