Ths is probably the nicest 2+1 gooseneck I've seen... http://www.horsetrailerworld.com/home/trailerdetail.asp?ID=363360

Most all of the mfg's are building a 2+1 gooseneck, not seen a BP yet. I have a Gore two horse BP with a side ramp and dressing room. Gore, Hawk, Blueridge, Sundowner, Adam,  as well as others build two horse BP's with side ramp and DR. Not enough room in the side ramp area for that third horse, if there was room, it would be too heavy on the BP hitch. My tongue weighs better than 900# loaded  with two horses, and all our gear in the tack room and a few items in the side ramp area.... Probably should have gone with a gooseneck, but I wanted someting I could pull with a 2500 Yukon or Suburban, Avalanch or 3/4 ton pickup...

Retento is right, there are several manufacturers that make nice two horse straight load bumper pulls with side rams.   I wouldn't call it a 2+1 however, as there is not room for a third horse.

You should be able to buy a new 2+1 gooseneck in the $24,000 to $28,000 range, including side ramp, rear ramp, box stall divider, dressing room, etc.  If the divider wall is on a slant (some are slant, some are straight), pay attention to which side the side ramp is on.  If the wall is at a slant, the ramp needs to be on the passenger side so that you could run a golf cart of other vehicle up the side ramp and not run into the wall.  Also pay attention to the width of the side ramp.  This could be important depending on what you plan to load up that ramp.