My situation doesn't EXACTLY parallel yours, but this I can relate.
The TDM400 FXO WILL pulse dial WITHOUT any patching. E&M wink doesn't seem to relate to any but the T1/E1 cards
What several us are doing is using an FXO card to pulse dial into either an incoming selector or station line of electromechanical switches. ( so that makes your PBX a youngster )
We have a private network of interconnected Asterisk boxes, a specialized ENUM DNS reference point that allows dialing between these antique switches. US, UK and NL collectors are all participating.
A few "gotchas"
Pulse dialing on the FXO most probably needs to be loop rather than "kewl". Any reversal of the loop from your PBX probably will drop the call, though there are options that you can try to change that.
the "w" in the dial string DOES NOT work in pulse. Under the sheets Asdterisk plays a sound file of silence when it sees the w, so in pulse it doesn't even pause!
IF you are to use an FXS module, also be aware that the Grount Start, or Earth Calling function seems to have stopped working around the introduction of 1.2 stable.
It seems to still work in the trunk versions though. This isn't directly related to what you are trying to do.
Finally, really consider the Sangoma A200 card. Somewhat less cost, here in the US, works with MANY more motherboards, and their support, at least via phone is good.
I found a defect in their FXS driver in pulse dial that should be in the current, though still beta, release.