Does Duo-R also imply Duo-RX?
I went the PC Engine + Interface Unit +CD-ROM2 unit path and I regret it. Ends up costing you more money and the hardware tends to be unreliable. Good from a collectors point of view, not so good from a gaming point of view. When I achieve a working setup (still waiting on a replacement interface unit), I'll probably be too scared to use it in case it breaks!
I think for my everyday PC Engine gaming needs, a Duo-RX modified for RGB is going to be my next purchase.
P.s. Hi Tighe, SentinelGames from YouTube here, thanks for all your help.