I've never run one, so I'm just throwing my uninformed .02 here.
If you're hung up on a 14 bolt pinion guard, you would be hung up on the 14 bolt otherwise. I can't count the number of times I've had to back up and either try a different line or give my rig a healthy bump to get the rear diff. over an obstacle. I've completely trashed a driveshaft and caused further damage to my rig trying to get it out in front wheel drive because I didn't have one.
IMHO hanging up once in a while is better than breaking parts that nobody carries spares of.
Sope - I believe he's talking about flanges for u-joints, like Toyota and some other manufacturers use. They protect the u-joint a lot better than a standard u-bolt/strap yoke. I'm sure there's some obscure source for them, but I've browsed the Neapco catalog many times, and haven't found any. HAD makes D60/D70 and 14 bolt flanges to bolt to Toyota driveshafts, but the 14 bolt one is almost $300