Your concerns were my concerns when I designed my system (albeit for different reasons). Check out my system for some commentary.
However, you may also want to think outside the box to help solve your problem. What does your listening space look like? Do you generally listen near-field or far-field? Could it benefit from acoustical treatment? Sound-absorbing panels may help decrease the noise floor while containing your music from reaching your neighbors. How about a good headphone setup for late-night listening? $4k to $5k could hire a mime to entertain you on the weekends and after-hours. At this point, I'm not sure new equipment is the solution to your problem.
However, you may also want to think outside the box to help solve your problem. What does your listening space look like? Do you generally listen near-field or far-field? Could it benefit from acoustical treatment? Sound-absorbing panels may help decrease the noise floor while containing your music from reaching your neighbors. How about a good headphone setup for late-night listening? $4k to $5k could hire a mime to entertain you on the weekends and after-hours. At this point, I'm not sure new equipment is the solution to your problem.