I managed to get my 2x R9 280x vapor x working @ 375kh/s each

here are my settings:

setx GPU_USE_SYNC_OBJECTS 1
setx GPU_MAX_ALLOC_PERCENT 100

cgminer --scrypt -o stratum+tcp://stratum12.dogehouse.org:9091 -u x -p x -I 13 -g 2 -w 256 --lookup-gap 2 --thread-concurrency 8192 --gpu-engine 1076,1072 --gpu-memclock 1500,1500 ---temp-cutoff 85 --temp-overheat 80 --temp-target 75 --auto-fan


,
"intensity" : "13",
"worksize" : "256",
"lookup-gap" : "2",
"auto-fan" : true,
"gpu-fan" : "70-80,70-80",
"gpu-engine" : "1076,1072",
"gpu-memclock" : "1500,1500",
"gpu-powertune" : "10,10",
"thread-concurrency" : "8192",
"expiry" : "30",
"gpu-threads" : "2",
"scan-time" : "5"

Temperatures are 59 for first and 70 degrees for the second one.

Any recomandations for some risers? I can't seem to make up my mind on what I see online.