Welcome from Sioux Falls. There's some good reading here on powerhammers. Start at the forums page and click on the powerhammers forum. You'll get this
http://allmetalshaping.com/forumdisplay.php?f=31 .
Rockhillwill has a very well documented build thread here
http://allmetalshaping.com/showthrea...t=3261&page=19 . It's no small project starting from scratch.
You need to ask yourself, is this the tool I realy need?