The score is probably 3 - Nil to the Dauphine
There are 3 basic options 4 if you include a VW pan, but we'll scrub round that one
1. Don't. Use the bits from a Dauph G. This would give better brake options and that's about it.
2. Fit a complete R8 front end (this is what I did ) It is not as difficult as you might think, but it does require some cutting and welding, as the complete R8 crossmember will be needed.
3. Make up a sort of Dauph / R8 Hybrid
Your Dauph is a '57, so it rolled off the line when the R8 wasn't even an itch in it's Daddy's pants, so it has a Dauph crossmember. Later Dauphs have a sort of dual crossmember and are easy to convert, but that is not an option
The R8 bottom arms and front uprights would be a straight nuts and bolts job to your existing crossmember. It is the top arms that cause problems.
If you can get me some pics of your front crossmember towers where the top arms fit, I can have a go at some suggestions . It may be possible to make conversion parts , so that the R8 top arms can be fitted here are some pics which explain better than I can
My Dauph with its front crossmember removed, we took the opportunity to reinforce the chassis legs at this time

The NOS front crossmember I had in stock. I made up a Gordini type tower brace. The small holes with tubes fitted are the R8 top arm mounts, the bigger open holes are the Dauphine top arm pivot point, but without the tubes. Post '64 or so Renault made only one crossmember and fitted and brazed the tubes depending on which car it was for. You can see how your towers look compared to this type
Finally this is a '57 Renault 4CV front crossmember tower (this type were detachable and I wonder if yours might be) This was going to be a proto project and I fitted and welded a steel bar into the top mount hole Then drilled and tapped it to take bolts for the ally block to give the R8 mount point. It did all fit together, but tragically was scrapped (not by me ) WE might do something along these lines on your car if you don't fancy the whole crossmember route
Want your thread filled up with mindless shite?? I'm your man!