Template:RunTROrTRSUnbalanced
You can use TS (Tip Sleeve) unbalanced cables, or TRS (Tip Ring Sleeve) balanced cables, but since the ¼ inch phone connections at the Bose Powerstand are unbalanced there is no particular benefit using balanced cables.
¼ Inch Tip-Ring-Sleeve (balanced) to ¼ Inch Tip-Sleeve (unbalanced)
This should work fine.
¼ Inch Tip-Ring-Sleeve (balanced) to ¼ Inch Tip-Ring-Sleeve (balanced)
This should also work, but likely no better than a simple ¼ Inch Tip-Sleeve to Tip-Sleeve cable. This is because the ¼ Inch input on the Bose System is Tip-Sleeve (unbalanced) anyway.