I know you said the 300 was not a good case in an earlier thread but I disagree. it has better airflow than the vast majority of cases out there including ones that claim to be high end. my temps on the gtx470 were the same that reviewers got so again the card will run hot no matter what case its in.
I agree with this 100%, the 300 is not a bad case so dont let them scare you away from it.
Look at my system in sig, i was able to obtain those listed overclocks in my antec 300 with 35c ambient temps. And it will take a 10.5" card no problem but you will lose 1x3.5" HDD bay.
Load it up with fans and it will not disappoint you. Cramming that Noctura in there though was not the most fun i have ever had i can tell you that.