You would need to modify the prices.aspx.cs page in the admin section. First, in RenderContents change
Code:
writer.Write(" <td align=\"left\" valign=\"middle\">SKU</td>\n");
to
Code:
writer.Write(" <td align=\"left\" valign=\"middle\">MFG#</td>\n");
Then further down in RenderContents change
Code:
writer.Write("<td>" + DB.RowField(row, "SKU") + DB.RowField(row, "SKUSuffix") + "</td>\n");
to
Code:
writer.Write("<td>" + DB.RowField(row, "ManufacturerPartNumber") + DB.RowField(row, "VManufacturerPartNumber") + "</td>\n");
We don't key off of the SKU when making the changes though, so this change is purely cosmetic (and perhaps helpful in finding the items you are looking for).
To change the filters, you would need to modify the sql query (also in the RenderContents method...in 8.0.1.2 C# starts around line 173).