There is nothing wrong with Indigo + Insteon, but you have other options. I'm going to mention a few and talk a little bit about price just in case that is a concern (it certainly is for me!).
Like Dan said - getting a dedicated controller is another good option. I also have a mac (which I love!) and a Micasaverde Vera 2. I'm very happy with my Vera. It is about $240. It works great from the Mac as you interface with it through a web browser (or iPhone App). It only uses a few watts so you don't have to leave your mac on all the time. Radio shack has been having a big clearance on z-wave and many stores still have 2 and 3 way dimmer switches for $15. That is a great deal for z-wave dimmers. They are out of stock on line but I saw some in a store last week. I also picked up a Trane Z-wave thermostat for $59 about a week ago there. Catalog #61-228, item $3888273. If you have the catalog number for a product and it is in stock in any store they will have it shipped to your local store for free. You can also print out a $10 off $40 coupon that is floating around online for an even better deal.
Anyway, that is one option. About $250 + $75 for 5 lights and $50 for a thermostat. Z-wave is a great technology, and the Vera 2 is very well designed, has a slick interface, and has an active community. It is built on the DCE router from the LinuxMCE project, but has gone through a lot of development in the past two years, and is readily extendable to add support for arbitrary devices with an easy scripting language named Lua (very common and easy to learn). Small startup, but very smart people with a well designed and open API.
One nice thing about Indigo is you could use it with the X10 cm15a (powerline and RF transceiver) and any X10 hardware. That is certainly the cheapest way to get into HA. I just bought a refurbished cm15a from X10 for $20. If you catch a good sale or by from ebay it is shocking how cheap X10 components are. The MS16A (newest X10 motion detector) is about $6, door and window sensors (DS10a) are about $2.50... etc. You could buy a complete setup for well under $100. It is not as reliable as newer technologies, but all my stuff works, it just takes a little effort. X10 has a really big following. There are some new products that supposedly help troubleshoot and correct X10 network problems too (including the XTB-IIR and XTBM from Jeff Volp). A lot of people write off X10 but it is cheap enough I included it in my setup and I've been happy so far.
You have a small place so concerns about RF range aren't such a big deal, but you might have to track down powerline noise sources. I expect you might have to do a little of that with Insteon too - but it is probably more reliable than X10. I have no experiance with Insteon. Z-wave is probably a bit more reliable. My z-wave network is rock solid.
If you are comfortable with a little bit of coding... another option is Mister House and X10 or Insteon. Mister House is an open source project that has been around for a long time. There are a couple of newer options too. There is a home automation message passing standard called xPL that seems to have a lot of support. Mark Hindess has a nice perl package for that protocol (xpl-perl) and just a few weeks ago released a project called Zen Automated Home that provides a web application that runs on top of xPL-perl and seems to have support for a wide variety of protocols. You can build all of this code on your Mac. If you go down this path you will want to install Xcode from Apple (3.x is free and all you need, 4.0 is $4.99 from the App store), and then macports. Install Perl from mac ports instead of using the version shipped with OSX.
You also could run any of the Windows or Linux options under a virtual machine on your mac. VirtualBox is free from Oracle or there is Parallels and Vmware. My experience is that Parallels and Vmware have better usb support - I own both and don't regret either purchase. You could also try out Premise on a VM.
Good luck!
So it really seems Insteon with Indigo is the way to go for what I want. Much appreciated.
