I would use balanced ports if your sound card supports them... the inputs are physically different, so it's not possible to plug in unbalanced into balanced or vice versa.
The XLR / Balanced connections cancel out any sound that might be added due to running speaker cable near power adapters etc, and may give you the more accurate sound. However, if the length of your cable is only a few feet, you may not notice any issues running unbalanced cables (my cables are RCA / unbalanced, I run them 15 feet with no issues).
Edit: I missed the part where you mentioned the sound card you intend to purchase... from the specs listed here, it looks like you will have to run unbalanced cable: http://www.m-audio.com/products/en_us/Delta1010LT.html