I can only speak for the one time we went to Coors Field, which was about five or six years ago -- the game Sammy hit three homers before being lifted in the sixth or seventh inning. We got three tix on game day and sat way in the top deck, just below the purple row of seats indicating the "mile high" point. In spite of that, the sightlines were great! It's a nice park and, unless the Rox are in the thick of the race, you should be able to get tickets without much problem. It's in a bar-ish area like Clark and Addison, so there are places to go before and after the game and taxis to take you to and from your destinations. And Denver's absolutely beautiful. Sounds like you should have a good time. And congrats! Dan