The Pigtail is almost identical to the TonePros in construction/dimensions, but made of aluminium not zinc (or whatever the TonePros is). The Pigtail is just a little less tall, if overall bridge height is an issue. Both are a good fit on a PRS.
I think aluminium is usually better for a one-piece bridge, but not convinced it makes so much difference when you add adjustable saddles. On a thin-sounding guitar I think the extra mass of the TonePros might actually be a (slight) advantage, but it's quite unpredictable I think.
If you do order a Pigtail, order the studs at the same time - they're a very tight fit, so you don't "need" locking studs, but if you order separately the bridge may not even fit the studs. I made this mistake and had to file the plating off the bottom of the bridge to make it fit. :(
I like the TonePros locking studs - not sure they make much difference to sustain or tone, but they stop the bridge tilting forward and it doesn't fall off when you change strings.
I'm not familiar with the ABM, but Rockinger sell a Duesenberg bridge:
http://www.rockinger.com/index.php?cat=WG084&lang=eng&product=3657C%2F3657G&sid3=425a32bf1439ec862e53bf5030139f50And StewMac have a few different models, including the Pigtail and this Schroder:
http://www.stewmac.com/shop/Bridges,_tailpieces/Electric_guitar,_non-trem_bridges/Schroeder_Stoptail_Bridge.html