pretty much straight up would recommend using autocad to do this as you can use a thing called Publish, it will batch PDF as many DWG you have got.
First question why are you trying to create PDF's of the model space? are the drawings set up with Layouts? using title blocks and viewpoints? if so there is no need to print model space as that is a working area.
Now to the main part.....
Open the first DWG in autocad and go to print it and set it all up as you would want it to create a PDF, once you have it setup you can see where it says page setup click add and it will create a profile of the setup you just created name it whatever u want.
next apply to layout and close the plot window.
save the dwg.
go to the file drop down and look for publish.
a new window appears here you will see the drawing you have opened in a list, the begin with change where it says 'publish to' change it to PDF.
Go into Publish options pick a location where you want to save and change to single sheet file type.
next click on the little button looks like a cad file with a + sign on it, once there you can add all you drawings, BUT first it says inclue and will say model and layout, change to only layout, then select what you want and click select.
will add all the DWG into the list.
oki order them that the first drawings is at the top then select all. hover over page setup for the first drawing select the Page setup you created at the beginning.
once done all should say the same thing here.
then unclick publish in background and unclick open in viewer when done.
then click publish and away they go.
now this is a pretty rough explaination but should work if not come back here and say what went wrong and will work it out.
Hopefully that helps.