What is the perception of foreign Universities (Non UK) in the US for prospective academic positions (Postdoc/Tenure)? First of all, I know that your work speaks for you, and if you have really good papers, you have better chances, but just bear with me, and for the sake of argument lets assume that your research is only one of the points to consider.

I did my undergrad in what could be considered the best University in my Country (Mexico)and got a Magna Cum Laude.

And then, I did my Graduate studies in the University of Tokyo publishing a couple of Journal Papers (I'm really pushing for that 3rd one!)

This question is directed to people in the US, since I'm looking to find a permanent position.

What is the perception Universities in the US have of foreign Universities? I happen to know that UK Universities like Cambridge and Oxford have no problem (for obvious reasons), but a professor friend of mine told me that other Universities are just not that well known. And having a degree from the Hawaii University was better than having a degree from Tokyo University. (As a side note, he is a professor at Haw Univ, and he wanted me to apply over there)

I just want to know how true or false this is, and realistically speaking how hard/easy is to get a position as a postdoc and eventually a full time professor if you are not from a US univ.

For example, do I have the same chances as someone who graduated from a top University (your Ivy leagues, Public Ivy League, MIT, Stanford, etc) or do I least have the same chances as middle range Universities?

As a side note, I have a postdoc in the UCLA lined up, so I guess that'll boost my chances a bit.
I don't think there's as much of a perception problem with foreign universities as you might think. I'd say the majority of postdoctoral associates are international, and most of them have not gone to universities as well known as Oxford and Cambridge. More likely than not, forging personal connections with the advisor you want to work for as a postdoc will matter much more than the university. 

That said, individual professors may have a bias toward hiring people from "known" schools, because the risk factor associated with hiring them is presumably much lower than someone from a school they've never heard of. Such a bias is of course understandable, but it also means that they could lose out on some potentially promising candidates as a result.