Congrats, keep an eye out for Sean Kelly's Multicart which he releases in batches every few months on eBay. Well worth the price to have all those games on the Veccy.

Protector is a great homebrew that you can grab here for cheap:

http://www.vectrexcarts.com/

And John D's great website has his games and the spiffy Genesis pad that is converted to a Vectrex controller, can't beat it for $20:

http://www.classicgamecreations.com/

You probably know all this info but all new Vectrex folks should also know