super search will find existing discussions on this topic, including Pi Zero. You likely want to use the v3 Pi, since it's more powerful than any of the others. An appropriate web search will find you a great deal of benchmarks of the various Pi devices, and comparisons to other single board computers which are on the market.
You can tweak the stock Debian fork for better performance (referenced in the link above) Currently Raspbian only has 32 bit builds. Other OS are available.
Given the number of competitors available it'd be wise to consider them.
Are you posting in the right place? Check out Where do I post X? to know for sure.
Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
<code> <a> <b> <big>
<blockquote> <br /> <dd>
<dl> <dt> <em> <font>
<h1> <h2> <h3> <h4>
<h5> <h6> <hr /> <i>
<li> <nbsp> <ol> <p>
<small> <strike> <strong>
<sub> <sup> <table>
<td> <th> <tr> <tt>
Snippets of code should be wrapped in
<code> tags not
<pre> tags. In fact, <pre>
tags should generally be avoided. If they must
be used, extreme care should be
taken to ensure that their contents do not
have long lines (<70 chars), in order to prevent
horizontal scrolling (and possible janitor
Want more info? How to link or
or How to display code and escape characters
are good places to start.