Hi, MK6 boards are universal so it will work fine from that point of view. So, yes this will work.
However, converting from MK5 to MK6 is pretty easy just some dumb little things.
The CRT screen will need to be adjusted slightly.
The door switch terminals are in reverse, so rip out the bottom door switch and just swap the terminals around, I can't remember exactly now, but its either connecting the terminals together or breaking the connection when the button is pushed in. (just use a paper clip and sticky tape to test, takes 2 seconds). - Note this is mostly a problem when you reset the static ram, as in, the door 'is open' but it thinks its not.
Some games have a 'cash box' error, that's easy to fix, just make a loop between 2 pins on the backplane. (On an Aussie backplane, P22 - Join/Pins 21 & 20=ground)
Notes: If you haven't used USA software before, you need setchips to get new games working. As 'Don Indallas' said, you will need a system riser board too. That board on ebay might just 'plug in and play' by the looks of it if you are lucky they set the game up.