HoshiChiri

If you can do it yourself, contact @MacRorie and order a UAV board for Composite/S-Video output. If you can't do the work, contact someone like @-^Cro§Bow^- to do it. I haven't had him do work for me, but I did use his fantastic illustrated guide to mod my own 7800, using a UAV from MacRorie. Both are aces in my book! And Rikki & Vikki looks AMAZING on my modded 7800.  

Oh Yeah!

That is one Fantastic Game!!!  I played it a bit when I first got it, but need to get back into it!  FWIW,  My 7800 is S-Video and A/V modded, but it's weird... for 7800 games it looks stellar in S-Video...2600 games wash out and the color slightly changes across the screen, and so they look better in A/V out for some reason...

@GoldLeader - there are separate color potentiometers inside the 7800 for the TIA and MARIA color outputs. They don’t change saturation but they do adjust color hue. Tweaking the TIA color pot might make just enough difference to prevent any kind of washed out look.