As far as the crotch strap, for thick suit the 2 inch works better, while for body suit or
thin neoprene the 2" rubs on my thighs, so I chose 1" for my aluminum warm-water plate.
You can buy the harness premade cheap from   http://www.diveriteexpress.com/    three
styles.

Adam

#I recently purchased a backplate and I'm now in the process of acquiring the
#necessary parts to correctly rig it.
#
#Approximately how much 2" webbing is necessary?  I've seen 12' and 15'
#quoted by various sites.
#

12' is probably enough, but since it costs pennies a foot, why not buy
extra and make sure everything fits well.

#Should you use 2" or 1" wide webbing for the crotch strap?
#

2"

#Should you use the plain or serrated keepers (aka tri-glides)?
#

I have plain keepers on both my rigs, and they don't slip

#What is the best source for acquiring these sort of items at the best price?
#
#

www.reefscuba.com

I prefer 2" for the crotch strap, but I use the softer webbing that
comes on the Trident weight belts (ya need the stainless buckle
anyways, and this gets you a crotch strap and stainless buckle for $8)

You want serrated tri-glides for the shoulder D-rings, stops on the
lower corners, and the left hip D-ring.
You want non-serrated tri-glides where you need to thread the webbing
through twice (scooter D-ring on the crotch strap).

Also see here:
http://www.baue.org/images/galleries/view_album.php?set_albumName=equipment

http://dir-diver.com/en/equipment/backplate_adjustment.html

 --- Rich
 http://richlockyer.tripod.com/

I would think that either would work fine.  The stuff is cheap and buying
more than you need is a sure way to be sure you have enough.

Personally, I removed the crotch strap.  It adds nothing of value to my
diving.  Most use 2 inch, assuming that the slot in the plate is 2 inches
wide.  It was only one inch wide on the original Halcyon models.  The
webbing for the crotch strap is not the same as what you use for the
harness.  The crotch strap material is much softer and more flexible.

Either works fine in this application.

I got replacement strap for mine from a friend.  You can't get any cheaper
than that.  Scott Koplan makes plates.  Since he's a member of this forum,
perhaps he has a source for the right kind of webbing, at the right price.

Lee