The second one (40-0038-00) is the over-under type which seems quite popular these days. You get the coin door and cash box in one unit. When I first began planning I intended to get one of those, but further study changed my mind.
Both of them provide you with a small opening into the front of your machine. Which may or may not matter depending on how your machine is built. . . My cabinet has a solid front, so I actually go through the coin door to hookup my computer, access the CP clamps, adjust audio volume. For me a larger door is more convenient.
I got one of these. . . .
http://cgi.ebay.com/COIN-DOOR-FOR-ARCADE-OR-PINBALL_W0QQitemZ180240698801QQihZ008QQIt was considerably less expensive than the Happ door. Looks good, works well. I put an old 30 cal ammo can under it to catch the quarters.
My only problem has been related to your question about tokens. . . MultiTech Games wrote in their description that it's "available with US token or foreign mechs". I asked for token mechs, but it arrived set up for quarters. When I complained they said basically: "We can send you some instructions to modify it so it will accept tokens." Then they never got back to me.
The actual acceptor mechanisms are cheap and easy to exchange. The problem is the reject buttons with slots too small for 0.984" tokens to fit in. So they would need to be modified or replaced, and the little "25c" label would need to be changed. For now I've decided to just go ahead and use quarters in mine. I may later decide to change it over to tokens, or I may not.