OneChip MSX is a piece of crap, and it's rapidly become too expensive to bother because they weren't mass produced. You can get a real machine for less than a OneChip. A solid MSX machine that does what is required can be purchased for <200$. FM cartridges run around 40$.
There's a handful of issues with a OneChip, so you're better off just emulating if you don't want to buy a real one.
some other great MSX games that aren't Konami ones:
MSX1 (yeah, the scrolling is doofy at times. Looks worse on YouTube than on a real one):
This is Turrican done right.
This is the strangest action RPG I've ever played
It's weird but fun
It's Gulkave, and look, it scrolls smooth!
Better than the FDS one.
Another weird action RPG
There's also the Ninja Kun games like the NES ones, some other shooters, and weird arcade style games.
MSX2:
Yes
Yes
hnggggg (Play Super Laydock on MSX1 also)
and Runeworth's soundtrack just because
Basically, MSX hits this weird sweet spot where it's not balls to the wall like the X68000, but it's not all goobery like a PC-6001 or something. You get those quirky one off action arcade games from the early 80s, and then you start getting all the more elaborate stuff.
Xak, Fray, Ys, Sorcerian, Emerald Dragon, Legend of Heroes and Burai are all there too!
I think getting into that is probably more fun than a Marty/FM-Downs. You get some unique stuff, and also get to sample Konami's starting point.