Saturn modding questions (USA location, JP console)

I've got a white Saturn who deserves good treatment. FYI presently it plays burnt games, but is not region free. With that said, onto the Q and A.

Is there a mod to increase the internal memory capacity? If not, how about the backup RAM cart?
I don't know what games have compatibility issues when there's too much free space.

Who offers a fair range of services these days? It looks like it needs de-yellowing.
I can also provide a BIOS chip sitting around here. Forgot which version, but I'd prefer the Japanese boot logo for consistency. Maybe a nonvolatile memory mod too.

I'll consider NTSC/PAL video, just in case, if doable without damaging the console (no thanks).
Keep in mind Framemeister doesn't like improper 50hz/60hz mods.

 

I definitely recommend these guys for Saturn mods if you have the money, think they charge $40-50 for the BIOS install and whatever else you want. I buy some supplies off them so I can confirm they have pretty much everything you're looking for, they also have pictures of their installs which are pornographic in nature.

https://www.facebook.com/pancakesforsega/