Dave,the 1068 is an outstanding unit,for 2ch music it really excells,its easy to set up and operate,imo.The 1075 is a good solid amp and should do fine w/the 5s.The only problem I have is the price,the 1068 could go $1500 new,it sells for about $1100-1300 used.The 1075 sells used for about $650 quite often,new I would not pay more than $800.The set new would be a good buy at $2200+tx.I would make the offer and dicker a little maybe,if not I'd get the 1068 and find a used amp,for $1k you'll have lots of choices,especially used.
For musicality its gonna be hard to beat the 1068 @ anything less than $1500 new,imo.
Just thought I would mention that Audiogon has a 1056 for $800,its one of the best units period in that range,add a 2ch amp for about $500 and you won't do much better at $1300 total,again imo,good luck.
#1- KLIPSCH RF7's - RC7 - RS7's - RSW15 - Emotiva lmc1/lpa1 - Denon 2910 -Sony ps3- Cambridge Audio 640c - Sony 333ES ---- #2-KLF-20's RC3II- RB5II's-Onkyo 805-Toshiba hd d3 - Oppo 970