I'd tend to agree with the ecoinomist about running fewer cards on one rig and more rigs. My five card (280x) are a pain in the ass as compared to my three card 7950 rig. The three card rig has run problem free for a long while now whereas the five card rig there is always some issue I'm looking into. I understand your point and a lot of people run six card rigs but with as cheap as mobos, ram and cpu's are, it's really not a big deal to run more rigs with fewer cards... I'm pretty sure it's more cost effective to but I haven't done a spreadsheet yet to prove it!

I'm actually using SMOS which as someone pointed out is set up for the R9 cards out of the box. Just have to make sure you edit the crontab to turn off the auto donating. Otherwise it's been really rock solid for me.

And as far as SSH'ing in from work I just set up port forwarding on my wireless router so I can hit the rig from the outside world.

Good luck, get a bottle of asprin cuz you'll need it for all the headaches you're about to endure!