Listed below are two links to a list of K/9 and BB/9, by level, for Pirates draft picks from 2005-2011. 
Spreadsheet should be sortable (e.g., descending K/9 by all A+ pitchers).
Next step could be to add the int'l signings from that period, and all NH trade acquisitions that pitched below AA.

Links:
1) Google spreadsheet:
https://docs.google.com/spreadsheet/ccc?key=0Avh41Y1SacludGUyYXNCXzdtYk5icUVPMHB0LXVORGc

2) Downloaded Excel 2007 file:
https://docs.google.com/open?id=0B_h41Y1SacluZGVkNzA3YzMtZTY2Zi00N2FkLThjOTgtMzI1N2Q2MzQ1NDVk

A few notes:
- Google spreadsheet is editable.  If anyone wants to correct, re-structure, or add - I can add you.
- Each cell (one per level) contains the innings pitched and rates per year, using IP to weight the K/9 and BB/9.
- For 2005 and 2006, I left out many of the more obscure late round draft picks.
- Most, but not all, of the 2008-2009 trade acquisitions (Morton, Locke, Pribanic, etc) are listed.
- AFL numbers are listed at the level in which the prospect finished the year (usually high-A). 
- 2011 NCAA/HS numbers for 2011 draft picks are listed in the notes column.
- Fangraphs, Baseball Reference, Pirates Prospects, and Pirates.com were used to compile information.