1 oz for bittering is too much in the sense that, I believe it's wasted for bittering. With only 6 oz, I would not dry hop, but push all hops for whirlpool and late additions and try to get the IBUs ( if they are so important ) this way.
I like brewing Pale Ales without dry hopping and get great results with 7-10 oz of hops. Lots of late additions and whirlpool hops at a lower temp. get me enough IBUs, tons of flavour and aroma, smooth bitterness. I work my water so the sulfate goes up into 150-175 ppm and the chloride stay at around 50-60 ppm with a mash pH of 5.4, which works great for " hoppy " styles.
My thoughts around a similar brew would look something like:
0.25 oz ---> 60 minutes
0.50 oz ---> 10 minutes
0.50 oz ---> 5 minutes
1.00 oz ---> 1 minute
3.75 oz ---> 30 minutes whirlpool at 150-160F
Around 40-43 IBUs ( depending on your utilization rate during cooling down and whirlpool ), 5.2-5.3% ABV.