I've been growing DIY with CFLs in a cupboard for about a year and thinking about getting a tent all that time. I didn't know Secret Jarden did a tent the size you use until earlier this week, otherwise I probably would have got it ages ago, space is a bit limited here too. My new kit arrived yesterday, an almost identical setup, DR120W tent, 600w HPS cool tube, RVK fan, carbon filter and clip on fan. I wasn't sure whether to get a 400w or 600w light and seeing your success persuaded me that I could manage a 600w.
I put everything together yesterday, it took most of the day because I'm not very good at anything DIY. Unfortunately I'm having some heat problems and I'm hoping you might be able to help out. Can you post a pic of your tent that shows how your light and fan kit are set up and maybe the outside of the tent to see what you've done with the vent ducting? I live in a cooler area, though we're having a mini autumn heatwave this weekend, outside it's been about 75F. I set up my tent in the spare room, left it running over night and temps were between 82F and 92F. I was hoping to keep them below 80F, particularly with the cool tube helping out. You've had to battle worse heat than me, is there anything you've doone that really helped keep your temps down?
If you don't mind I could post a pic of what I've done so far?