I have a c2700-275 combo and its quite nice. I'd definitely move up to the c22 or c2700 over the c8 unless you really like that look.
dac2 board is quite good for the money as well. ARC in the dac 2 board is also very handy if you have a TV in the same room. the options on the c2700 make it the best preamp I've used for options and flexibility.
The 275 runs hot.
both need better tubes then the JJ's ( i believe they are JJ's) MAC supplies as OEM tubes not bad for new tubes but lacking in so many ways. almost every negative I've read above for the mac tube gear can be related to those tubes IMO.