I've done hundreds of these projects over the last bunch of years and a lot of good direction and tips given so far. Speed of workflow and recall is paramount. This stuff changes by the minute sometimes.
The one thing I would differ with is in regards to sound quality. This stuff has to sound as good as anything you might hear on the radio. It might not make a big difference when the day is done as they bury the music under the VO, dialog or SFX, but it's of utter importance in trying to sell your client who is making his yay or nay decision solely on how your music sounds by itself. While not necessarily music savvy, clients can tell if your music doesn't sound as good as the high budget produced song everyone was referencing. They might not be able to tell you what's off, but they can tell that something's missing. I know at one time nobody really gave a shit that the mic on the kick had fallen off the stand while cutting a jingle, but I can tell you that the guys that still have that attitude don't work much.
Forget the summing thing. Keep it ITB with the easiest recall possible and learn how to make it sound great. I'm in LA which is a Pro Tools town, but I know other people doing this using Logic or Digital Performer. I use HD192's and have no need for any higher AD/DA convertors. Converter differences are minimal IMO compared to other elements of the chain like mic's and mic pre's.
Try to buy or be able to rent one great LDC mic that is a great vocal mic and that works well on other acoustic sources. I finally dug deep and bought a Telefunken 251 and I can't tell you what a huge improvement it made to having that world class vocal sound. You don't have to go that nuts, but the one thing they all hear the most is the vocal so don't think you can skimp on that with a $300 microphone. Also try to get at least one great pre (Neve, API, etc.) Don't get all anal trying to pick one of these out. Everything in this league sounds great and will work great on most sources. Besides you'll end up getting more of these later on as you grow.
Try to keep your synths and samplers ITB for that ease of recall thing. The software synths sound great anyways. Software must haves for me include all the Spectrasonic stuff especially Stylus RMX. I've got a few drum related programs and the one I think rises to the top for programming drums is DFH Superior 2. I could do just about any project with just those programs and it would sound great. Logic also has some great sounding VI's as does Pro Tools. For orchestrated things it's nice to combine different libraries, but if I had to pick one it would probably be the Quantum Leap Symphony Orchestra library. I have the Platinum version, but for most things the Gold version will be great. Also, get the XP version too.
That about covers the basics. The rest of the items you mentioned like DAW controllers etc. would just be the icing on the cake.
One other thing worth mentioning is to try and use as many live tracks as possible time permitting. I may be biased on this point as I come from more of a song and record making background and my main instrument is guitar, but I think this is a huge factor in why I think my projects have an edge over a lot of my more keyboard oriented contemporaries. Keyboard players tend to think more in that sequencing mindset and are more prone to just keep sequencing parts. Since every time I pick up my main instrument I'm recording a live part that can't be note corrected or quantized I tend to think more in an old school record making way. This makes the music feel more real and more akin to a record. Sometimes just cutting a real tamborine part can make all the difference in the world.
Hope this helps. Don't steal any of my gigs