To answer your question as to which software will accept DXF imports, you will have to choose a software, check to see if it will accept DXF imports, if it does then proceed with what ever you wanted to do.
A few that may support this:
-Eagle only supports direct import of ACCEL-ASCII (aka PCAD ASCII) which can be exported from Altium, Protel, and PCAD. You can import others using a third party company like LogicSwap. Eagle actually as a page of tools and converters.
- AutoCAD I believe it's possible. It was difficult finding
information on such a popular software. They are the company that created DXF files. So that part is easy.
- Design Spark returned my email stating they can import Eagle using eip and eis files.
- DipTrace returned my email stating they can import the following PCB files: PCAD ASCII, Eagle (using our ULP that coverts Eagle board to DipTrace ASCII), PADS ASCII 2005, OrCAD Min Interchange. Moreover, DipTrace can import Gerber, NC drill and DXF files.
It seems that DXF is a safe bet. However, they all are different. You'll really have to choose a program then assess what are your best options.
Gerber file format is a leading format for PCB Design. It is exported by every software. Importing is a different story. It would seem that using a third party company is also a viable option.