Basic Recording Configuration

Question

I plan to buy a Mac Pro and Logic Studio to record music. I’ve spent hours surfing discussions, but most have been too specific and not enough big picture, so apologies for any overlap. I want to use as few hardware and software components as possible, among other things on the K.I.S.S. principle that that will mean fewer things to go wrong.
What will I need besides the Mac and Logic?
To the extent possible, I want to do everything inside the Mac, using only Logic (including plug-ins), and a mic and MIDI controller. By everything, I mean MIDI tracks, recorded from a MIDI keyboard, controlling internal plug-in sound sources, and audio tracks recorded via microphone (vocals and possibly guitar). And likewise apply effects to audio and MIDI tracks with internal plug-ins. Then to burn the final mix to CD or DVD or make available via Internet. Most if not all recording would be done one part at a time. Pro quality sound (e.g. 24x96) is a must. Portability is not necessary. A priority for me is getting everything I need now, partly because I don’t want to interrupt my music making with more learning curves next year or the one after once I’ve got this much down, and partly because I’ll need to use files created now perhaps years down the road with no questions asked.
Is there anything unrealistic about this goal? Such basic info as to what inputs and outputs each piece of gear has can be hard to come by or use unfamiliar terms. Do I need a separate audio interface? A separate MIDI interface? If so, which ones would be most suited for this purpose?
Any comments as to which Mac Pro? The quad-core and eight-core versions are both candidates, but I’ve been mostly focusing on the eight core just because it appears my target 16 GB RAM is quite a bit less expensive that way (probably due to using smaller sticks). The 24 and 30 inch Apple displays are also both on the table. At this time, I am only getting one hard disk, with the idea of adding one or more solid state drives later on, the lone exception to my everything-now rule. Thanks for your thoughts.

Answer 1

audio tracks recorded via microphone (vocals and possibly guitar).
You'll need an audio interface - I'd suggest something like the Apogee Duet or One would suit, being reasonably priced and good-sounding, and having enough inputs to record one or two things at once.
Any Mac Pro will do you fine.
If you get a controller keyboard with a USB port, you will not need a separate MIDI interface.
Alternatively, many audio interfaces also come with MIDI ports and will act as a MIDI interface if you just get a MIDI keyboard. If you go down this road, that requirement is something to consider when choosing your audio interface (I don't think the APogee's listed above have MIDI ports.)
Go for the 24 display, the 30's are expensive and possibly a bit too big for general use... ymmv of course.