The one thing you need to accept is the reality of a single pin collection. You can spend 8k on a MMR or Wonka. You can spend 3k on a TFTC or monopoly. If you are going out to play pinballs on location, you will get tired of any 1 game you have. I'm sure it's been said before, but you can't ask for help picking a game. If you love a game you make it happen. If you really want a IMDN or JP2 pro just find the extra cash. If you grew up with an attachment to any particular game (mine is Whirlwind) then hold out for that game.
If there is no one game you want, you just want a game for your house, then you need to start making contacts with other pinsiders. Dont limit yourself to any game. Buy the best deal you can find, flip on it for a few months, then list it for sale or trade. Once you do deals with people they tend to put you in their loop. Sometimes this gets you a game opportunity before it hits the marketplace.