As far as the Springfield XD goes, which round should i go with?
If you have decided on the Springer, well done! If not, may I suggest you look at the S&W M&P? I have been totally impressed with this gun, and pricing makes it reasonably attractive...
I will vote with the "shot placement is everything" group, and suggest that with the large variety of loadings available in 9mm you should be able to find a satisfactory round for your purposes, at lower prices than comparable rounds in .40 or other calibers. However, I also believe that you have to make the final decision as to which round serves your purposes; do the research, try to shoot both in your selected gun, (if possible), and see what works best for you.
Good Luck, and enjoy the process!