Creating and building the 4 channel amp would present a large investment of time and resources for what might be a very limited customer base. You could always go with the monoblocks or 2 stereo amps but I would think a model 5000 would be the best choice. Having that installed spare channel will be a godsend after the warranty is up. I currently have 12 channels of amp but only use 7 to power both systems. If I ever move to Atmos/DTSx systems I have what I need plus a spare channel.
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Music system
Model 990/7500/Magnepan 1.6 QRs/Technics SL1200 MK2/Aperion S-12 Subwoofer/OWA3/Sony NS75H DVD
APC H15 Power Conditioner

TV System
Large Advent Loudspeakers/ Polk center/Monoprice surrounds/Panasonic Viera 42 inch/Onkyo HT-RC260/Sony BDP S590/Directv


Home Theater System
Onkyo PR-SC886/Outlaw 7125 Klipsch RF-82 L/R,RC-62 center, RB-35 SR/SL, BENQ HT1075, Outlaw LFM1-EX/OPPO BDP-83/Directv
Harmony ONE
Blue Jeans and Monoprice interconnects
APC H15 Power Conditioner