Little update on a few things, I bought a couple of 120mm fans to put on the side behind the motherboard to cool the hard drives - an Antec Tri-Cool and a Yates Loon:
Yates Loon - had to plug this straight into the power (haven't got a fan controller) and although nice and quiet outside the case, caused vibration when in place on the sidepanel. Stupidly I hadn't thought to buy any anti-vibration stuff - d'oh!
Antec Tri-Cool - set to low or even medium this didn't move the same volume of air at all as the Yates, but high is just too loud. It also doesn't produce any vibration noise on low though, so this is the one that's in place.
My HDD temperatures are now not going higher than 35C with the Antec in place. I am planning on grabbing some anti-vibration stuff when I next order something, so my long-term plan is to put the Yates in place and see if I can keep them in the 30C-33C range.
I've also replaced the faulty rear 180mm AP fan with another (the one that came with the case switched off when set to High). Both fans now work properly on both low and high, and the new fan seems a little quieter than the old one on low but this might be my imagination. Both are set to Low all the time but now I might switch it to High mid-game and see if it makes any noticeable difference.
Also, I tried the front mic and headphone sockets last night for the first time, and I've got to say they're pretty stiff to insert into. The headphone went in OK, but the mic required a fair bit of pressure and didn't seem to go down far enough to engage first time. I am sure this will ease with a little bit of use but it doesn't feel great straight out of the box.
Overall, after a week of playing with it I am absolutely sure I made the right choice for me. I can completely understand people not liking the look (I personally do) but it really is the best thought out and built case I've ever used or seen. Based on this one, I wouldn't hesitate to recommend Silverstone cases to anyone.
Finally, wanted to say thank you to everyone for the kind comments about the build. They're all really appreciated - thanks!