Looks good Steve. Yeah its a tough choice between a tight loop and flexibility. You don't want the tubing moving around too much, as you can accidentally loosen a connection to a barb, etc (I had a swivel connector that loosened when I moved stuff a bit).
As for powering the pump, I strongly suggest folks invest in this little device:
Cables to Go USB 2.0 to IDE/SATA Drive Adapter Cables - CABLES TO GO - 30504
$40 at NCIX, but available at Canada Computers for less than $20:
Canada Computers | I/O Controllers, External Hub, Internal Bay Devices | Bytecc BT-200 USB 2.0 to IDE Adapter, Works with 2.5", 3.5" HDD and 5.25" CD/DVD Drive (BT-200)
This is a hard drive to USB converter. The kit comes with an IDE/SATA/Floppy connector cable, with a USB connector at the end. It also comes with a molex/SATA power cable for the hard drive, which will also power a pump....and it has a handy on-off switch to boot!
Here is a picture or two to illustrate:
Much cheaper than a PSU (unless you have an old PSU around), and you also have an adapter kit to use for diagnosing and recovering folks' hard drives.