I recently rebuilt a system using a Pentium G3420, which I got during the Christmas sale for about 50 euros, which is very cheap for a CPU. I coupled it with a single stick of DDR1600, the higher rate being the primary selling point of this chip over, say, the G3220.
You didn't make much use of the higher bandwidth possible if you only used one memory stick - two ddr3-1333 with a G3220 would offer a lot more bandwidth
In any case, neither ddr3-1333/1600 nor single/dual channel will matter much for the cpu, though single/dual channel probably does make some difference with the IGP (though it is only GT1, hence the difference will be nowhere as big as it would be with the GT2 parts).
FWIW in that legitreviews review it looks like they were able to overclock the memory to ddr3-2133 even. Not sure why I thought that was locked down too, maybe the board can chose to ignore it or play some other tricks (my board definitely doesn't allow it with a G3220, the only faster option aside from ddr3-1333 is ddr3-1400).