I got mine from Mancini.... The caps are bolt on though not like the picture. It is Billet.
Driveshafts I get from Curtis Tatton. $225.00 Delivered to your door 3.5" or 4" with 1350 Spicer U Joints ready to go. He has guys throwing 1200 HP at them to the tires. He says has not broke one yet.
http://www.manciniracing.com/ma90413cosly.html