Francois,
What do you want to use them for exactly? By that I mean, you do realize the difference between these Gunze products? I have used Mr. surfacer spray 1000, and Mr. Resin Primer, both were gray in color. For me, the difference was that Mr. Surfacer 1000 dried and left a subtle grainy, almost chalky like texture to the model (I do not mean to imply that it rubbed off) - just like Tamiya's Fine Surface Primer (White) whereas Mr. Resin Primer dried with a smooth, satin finish. As for Mr. Base White, I suspect that it will be identical to the Mr. Resin Primer.
Mr. Surfacer 500 is a totally different beast - and I recommend it in a jar form. I do not recommend it being used as a primer as it will dry with a very noticeable grainy texture. Here is a pic of what Mr. Surfacer 500 looks like just after 2 applications.