it would be very hard to push good enough mobo and psu in there under that budget the 8 core fx chips are power hogs, boards with bad vrm desing have trouble maintaining stable clocks for these chips, if i may ask as to why do you want the fx 8320 as your cpu, are you planing on doing some video editing( since in gaming all those cores are useless and any i3 performs better plus the mobo for i3 would be a lot cheaper)
well i would go for something like this
http://uk.pcpartpicker.com/p/kczJ23
, but its already a bit out of your budget and that is without any case, though you can probably change the psu to a cheaper one(i wouldn't, but you can do that) and get a cheaper board(i would not go for anything lower for 8 core chip)