Both the T and S series will run the programs you need without a problem. After all, they both have ver similar hardware specifications. I can understand that you don't consider gaming-on-the-go important... the people who usually care about gaming capabilities are people who go to LAN parties, or business travellers that want to play games when they get to a hotel at the end of the day.
I would not eliminate the S series from consideration... I own an S-series, my boss owns a T-series, and I find his laptop too small to use comfortably. The keys are smaller, the screen is smaller. For me, somethign like the Sony S-series or the Dell Inspiron 700m are the perfect size from a useability and portability standpoint. In fact, I think that the only allure of the T-series is that it comes with built-in wireless WAN (either through Cingular EDGE, or Verizon Wireless EVDO).
If you do not care about the wireless WAN, and just want a small laptop with great battery life, I would also consider checking out the Dell Inspiron 700m, the Sharp M4000 Widenote (6hours of battery life!), and Asus W5V. All are great, small laptops that might provide an alternative to the T-series, if all you really want is a small laptop.
And you will want at least 1GB RAM, regardless of what programs you run. I highly recommend that you just upgrade the RAM yourself, rather than buy from the laptop manufacturer. You'll save a bunch of money that way.