Record already comes with Line 6 Guitar and Bass POD. At least it did when I beta tested it. You are right the mixer sounds really good. I just don't understand why you would want to get an external POD when a version of the software is already integrated into Record. There isn't any extra functionality added with a POD interface with Record, to the best of my knowledge.(Other than the amp Sims on the POD Interface itself.)
Then if you decide to run Pro Tools, buying the Micro just doesn't seem like it would be a good decision considering the Micro and the Mini are about the same price and with the Mini you can record vocals or DI a guitar or bass straight into Pro Tools and Record. Whereas the Micro gives you a headphone out, and that is it.
If you are just running Record and Reason Standalone for right now then the Mac Book sound card is fine because it is all In the Box, there isn't any conversion going on. Plug your head phones in or some external speakers and away you go no problems. In fact that is what I'm going to do when I fix this old laptop up. I'm going to put Reason on that and I'll just plug a 25 Key midi controller into the USB port and Headphones into the computer and sit there and make beats all day when I'm not at home.
The thing about Record is that you can get the MBox Mini and just use that as an interface to record a Guitar or Bass or Vocals into Record, and then when It gets time to send your songs off to the Mixer you just Rewire Reason Record into Pro Tools set up an Instrument track and Audio track bus the output of the Instrument Track to the audio track and hit record, don't forget to set your tempo in Pro Tools. Do a save as in Pro Tools, then delete your instrument tracks in the session and send them off to the Mixer.
Now that is if you decide to go the Pro Tools route because as you have already mentioned you can go the other route and just stem your tracks out and send them to the Mixer that way too. That is up to you, but if you decide to go the Pro Tools route I would at the very least get the Mini. The Micro is made more for people that travel a lot and they like to get work done while traveling, the thing is they already have another Pro Tools interface at their main place.