2. Running at 15% grade
3. Under $1,000
Honestly, I think you're looking at a gym membership.
You'd be hard pressed to find a quality, sturdy enough machine to meet those needs for $1k. Maybe you can get one used, or even an old reconditioned one - but I just spent twice that on a Sole F85 at Sears and it was the best "consumer grade" machine (as opposed to a professional or gym quality one, which new would set you back even more) I could find for my more modest needs. Maybe a lower model Sole would work for you - the f80 of other - but even still, you're looking at $1500 before delivery.
I think there is a website - treadmillreview.com?? - that may help you in you search.
2007 Seven ID8 - Bontrager InForm
2003 Klein Palomino - Terry Firefly (?)
2010 Seven Cafe Racer - Bontrager InForm
2008 Cervelo P2C - Adamo Prologue Saddle