SCART to HDMI, that's interesting. Personally I would prefer the least upscaling as possible but if you're using a modern TV that's inevitable anyway so it should work just as well. Perhaps better, considering the TV might not need to process it internally.
As Apollodude mentioned in passing all models of Genesis except the Majesco Genesis 3 have RGB capable ports on the back. The Genesis 3 can be RGB tapped from the motherboard (and has the best PPU for RGB or Svideo of all of them, oddly, just horrid composite) but in general I'd stick with a model 1 with the high def graphics logo like the TS has as the sound output on non high def model ones and model 2s has been proven inferior.
At any rate if you're handy with a soldering gun you could save even more money by building your own cables. Here are some pinouts for those interested:
http://www.gamesx.com/avpinouts/genesisav.htm