If money were no object, I assume you would just go on paying for studio time. As others have noted, there are more cost effective choices. But aside from the cost issue, there is more to optimizing your choices of DAW components than just the money. It is not all that uncommon for someone to buy or build a machine that has the best specs and reviews on the gamer sites, only to find that it is unsuitable for use as a DAW. No motherboard manufacturer is designing his board for audio, but many are aiming at the gamer market. Many of the features that look good on a spec sheet, will actually interfere with the smooth operation of audio software and hardware. Things that you do not need include raid, wireless, high end video etc. In order to get pretty pictures streaming for the gamers, it is common to steal slices of processor time from more mundane tasks that make audio run. Unless (and even if) you are very sophisticated at tweaking your machine, it may be difficult to turn off all the bells and whistles on a monster machine. The choices for the optimum DAW are constrained by the audio hardware and software you plan to use, and what you plan to do with them.
Your first choice in live audio recording is your audio interface. You need to know how many tracks you are going to be feeding into your computer, and how you are going to connect your interface. You do not need firewire (IEEE 1394) unless you are hooking up a firewire device. If you are planning to use a dozen microphones without combining them in an external mixer, you need a dozen microphone inputs somewhere. The best onboard audio (built in to the motherboard) is only going to have a stereo miniplug for input i. e. two tracks. What kind of microphones are you going to use? Do you need phantom power, or preamps? Are you ready for some major sticker shock when people start recommending professional quality mics? The good news is that audio interfaces tend to survive at least a couple of computer upgrade cycles, but if you guess wrong on the future of the connection protocol, you may find yourself stuck with an unusable device sooner rather than later.
The actual computer power needed to record a practical number of tracks without effects is quite modest. Huge memory is more useful to people using multiple instances of synthesizers and streaming orchestra-sized sample sets. Mixing and applying effects is not as demanding, and operations can be done on a few tracks at at time.
You do not say who will be using your equipment. Paying someone to do your recording, mixing and mastering, is not the same as renting his equipment. The dirty little secret that Cakewalk and their competitors do not want the world to know, is that using their stuff to get professional quality music is not easy. I would not begin to advise you on this, except to say that it may require as much time as it takes to learn to produce the music on a musical instrument to learn to record and process the sound into a professional recording.
I use Sonar as a hobby, and my product is far from professional. Sonar is more of a toy that makes my synths work, and I enjoy noodling with it for a few hous at a time. If I were looking to make a band sound good, I would probably be better off going to work at Walmart and saving my money to pay someone who knows what he is doing.