The aluminum block is called the "remote oil filter mount". Check out your local boneyard for a replacement.
Simple enough job and can be done without special tools. Don't bother with the dealership lines. If you buy the lines at the dealer, you'll get the same lines you have now, and they'll leak just like the lines you have now!
Most auto parts stores have replacement lines made by Dorman. They are cheaper, better quality and will last longer than the GM lines, but eventually they will leak too.
If you want to do the job one time, your lines can be modifed for about the same money as the repplacement lines, maybe less. Here's how:
http://www.automotiveforums.com/vbul...d.php?t=764277