If you donít have outboard gear, I wouldnít bother with Pro Tools. Logic and Cubase do just as good a job of mixing, and their MIDI editing is superior to that of Pro Tools, or at least it was last time I checked. I know PT has hit version 10 I think, but yeah, wouldnít bother.
You can mix to a sufficient standard in Ableton if youíre comfortable doing so. Itís just a bit different in practise than Cubase or Logic. If you were set on getting a new program, and were Mac based, Iíd go with Logic. Itís cheaper than Cubase if you buy it digitally from the AppStore, I think itís ~$200 and a lot less of a pain in the arse to install using digital delivery than discs.
Studio monitors is a pretty personal thing. It all comes down to how it sounds to you. I got some Pioneer SDJ-05ís, which are cheaper and not really heralded along with other monitors, but I like the way they sound. I would suggest taking a CD into Kosmic and listening to it play back over a few different sets of monitors. You donít need to buy from there, but itís worth making the trip and doing it. KRK/Mackie and Yamaha make decent monitors and all would be in the price range of those M-Audioís. But yeah, canít stress enough to listen for yourself and make the decision, not to base it on whatís popular or what someone said or what your mate has got. You might end up paying more for something that doesnít sound as good to YOU.
If going Logic on a Mac, then Apogee Duet 2 would be a good bet. Apogee make soundcards specifically for Apple systems. Itís about $550, but sounds great IMO. The inputs are fairly limited however, so if youíre thinking of getting outboard gear in the future, you could look at something else. Personally I have a MOTU Ultralite Mk3. It has a heap of ins and outs and MIDI in/out, and is also a hybrid meaning it has a USB port AND a firewire port. Pretty flexible soundcard.
There is a studio pics thread in this forum, towards the top I think. But any electronic music forum will have a thread for people showing off their setups (logic forum/Ableton forum/DOA/dubstepforum) so youíll be able to see what other people have.
With monitors, keep them off the wall and away from corners to minimise sound bouncing around, from there you should be able to read up on the internet about how to determine where abouts in the room you need to put bass traps.
eBay accoustic foam, you will get it cheaper from ordering overseas than you would if you went to an Australian retailed 9 times out of 10. There was one seller offering a 10 pack of foam pieces for something like $30 a while ago.
I had 8" KRK Rokits in a small room, everything I listened to throught them sounded shite so I sold them. I now have dynaudios with 7" cones and they sound sexual. I think KRK Rokit 8's a re fucking rubbish, but thats just an opinion. I have a 10" dyn sub too which I turn on every now and then with a switch and stand in the sweet spot of my room for a low bass check. its working fine.
Try at least 5-10 sets of monitors before deciding I reckon.
Don't settle for something in available budget either, if there's a pair of monitors you love the sound of but you can't afford, then save up. Monitor's are the most important purchase IMO and if you're serious about this you'll spend the first month or more learning your DAW and the basics. Though I guess you're already pretty clued up after using Ableton for a while!
If you want to extend the low end response in your HS80's you can disable the limiter circuit by snipping a jumper on the amp board. I've done this to mine with great results in my studio. You can go further with better op-amps and capacitors..