I don't have Bulldog extruders, but I have twin mirror image Wade extruders with a Bowden cables mounted on a Mitsumi extrusion across the top.
Only one extruder is shown fitted. It works well, but I still have difficulties getting two to work together. Getting them dead level is the main problem I have found. I had the two hot ends side by side on the X axis but it reduces the bed X axis width. The hot ends were just 50mm apart. I might try one in front of the other along the Y axis.
sorry for the small pic. I can't seem to resize it.
I have been trying to came up with a hotend design where the Z height is adjustable with screws.
Two extruders with drive motors weighs about a kilo. I figured this was a bit too heavy to have flying about at high speed on the X carriage, so I decided to go with a Bowden setup.
I print just ABS now so can't help with PLA.