Why you gotta be a bitch like that. Can't you just save up and buy both? A good backpacking tent is nothing, go get the REI halfdome 2 that shit is cheap. Cruise craigslist or ebay for a decent mountain frame and work your way to the top piece by peice, boom done you have both.
But seriously the trails around hilltop are pretty awesome and there are a ton of trails all through bicentennial/far north park that kick ass. You would do fine with a decent hard tail, maybe a 29er if you wanted. But most stuff up there isn't so crazy you need a super high end bike right off from the start.
And the REI halfdome is an awesome tent, very light and spacious, very inexpensive plus you get REI's return policy. You could even use that thing all year if you keep out of high wind and heavy snowfall. If you want something a lot more sturdy and rowdy enough for winter snows and the like I really love my REI arete 3 ASL. It's damn near the lightest double wall 4 season you can buy, but will cost you a fair bit more. Though I think I may even have an pretty nice old lightweight dome tent you could have for free, if I make up up for Big H's wedding I'll try to dig it out for you if you want it.