Hey guys, after searching high and low through the pie chart settings and giving up on creating separate columns showing percentages to use as the values, i discovered how to do it.
If, when you choose the values to use, if you open the drop down and select quick calc and where it says 'Show Values as' select % of Grand Total, it'll use the % of the total as the value, and if you choose to show value as the data label, it'll show the percent.
The only issue i've been able to find with it, is that if you hover over that section of the chart, it won't tell you the actual value, just the percentage. but hey, so did creating a column of percentages and using that as the value.