Hi,
Well according to Google "Currently, AdSense publishers may place up to three AdSense for content units on one webpage. This includes a maximum of one 300x600 ad unit per page. You may also place a maximum of three link units and two search boxes on each webpage. You may place up to three link units on a page, in addition to the three standard ad units, and two search boxes. " Reference: http://support.google.com/adsense/bin/answer.py?hl=en&answer=1346295#Google_ad_limit_per_page
Choices Theme has no restriction as to how many adsense blocks you place in your website. Just remember that you can't just paste that code into a Post or a Page since Wordpress restricts and filters most code tags for your protection (or any editor can just paste some javascript and take over your website).
Install http://wordpress.org/extend/plugins/enhanced-text-widget/ plugin so that you can paste the adsense javascript into it and override the restriction in a widget.
and/or
http://wordpress.org/extend/plugins/tags/adsense there are a bunch of plugins for adnsense on this page. Try a few and see if you like.
Thanks,
Nick