Welcome to the boards, madmansmith. I wouldn't feel bad about chopping up the old TurboGrafx if I were you. If it was a Supergrafx or U.S. Duo I might, but those TG16's have seen worse and there's still plenty of them. When doing your RGB mod, consider carefully where you put the ports; don't locate them where they'll interfere with a Turbobooster or CD attachment if you ever want to add stereo sound someday.
I'm also going to throw one vote on the side of not buying a CD console right away. NEC made a really cool family of consoles, all with slightly different flavors, characteristics, and idiosyncrasies that can be overlooked if purchased simultaneously. Turbochips feel different than early CD's, which feel different than Super CDs, and so on. When I bought my Turboexpress after years of owning a Duo, I was surprised how much it changed the games - it breathed new life into some and made others boring or unplayable! Likewise, when I got my Supergrafx from Dreamstars, I sat around that first day playing Aldynes and Battle Ace and it really did seem like an entirely new console. Same thing with the Arcade card.
Buying everything at once ruins the fun almost as fast as downloading every rom in one day (probably why Roy "Big Money" Vegas crashed and burned so fast). It's like putting a whole pack of gum in your mouth: awesome for ten seconds, then the flavor's gone and your jaw hurts.
You probably have at least fifty killer games at your fingertips with just the hucard/turbochip library, so, unless you're an RPG fanatic, take your time and enjoy the TurboGrafx-16 for a few months. The price inflation we've seen over the last six years has tapered off and there's plenty of time to worry about broken lasers assemblies, potentiometer calibration, CD system cards, different controller ports, $100 games, and keeping track of your save files on three different Tennokoe Banks later!
