I only have experience with one Doujin mod'd RX, and the RGB is great. The s-vid has a pink tint, but I do not use that video output so it does not bother me(RGB 4 life). I have not opened it up to look at his soldiering work, so no input there for ya.
If you have a Duo, prolly easier to solicit on the forums for a stateside modder to do your needed work. If you do not have any obey, he could be an one stop solution since Doujin seems to have Duo's listed quite regularly.