How can I create a beautiful letterhead from the article class using say header or footer . I do not want to use letter class due to limitations. The letterhead should look outstanding.

I have produced a letterhead as an article by using the package textpos and setting the origin of the paper to the lower left corner as the origin as well as using mm as a unit:

\usepackage[absolute]{textpos} % Positioning textblocks in absolute terms
\setlength{\TPHorizModule}{1mm}
\setlength{\TPVertModule}{1mm}
\setlength{\parindent}{0pt}
\textblockorigin{0mm}{0mm}


This then allows me to insert text such as the date, to and from addresses as text fields at exact positions using textblocks, in this case placing the page number and the date (note that the page number uses the lastpage package)

\begin{textblock}{5}(195,13)
\thepage(\pageref{LastPage})
\end{textblock}

\begin{textblock}{25}(114,35)
\today
\end{textblock}


I also add graphics using the put command. I actually define logos as new commands to manage them more easily

\newcommand\FirstPageLogo{%
\put(99,730){%
\includegraphics[width=33mm,keepaspectratio]{logo-org-english_rgb.pdf}%
}}


Note that in ths example the coordinates are in pt as determined by the \unitlength parameter but this can be changed by \setlength.

Using these code snippets you can place all parts of the letterhead components exactly where you want. There may be other ways of doing the same but I found this relatively straight forward.