You might look at Kronos robotics.
http://kronosrobotics.com/xcart/customer/home.php . The Dios is an 18 series chip similar to what's in the first controller. They offer several kits with different carrier boards. The programing language is free. It's much easier to get started with than the microchip environment. Check the web site out. There are allot of app notes to help you get started. It's a basic interpreter thats well implemented. You can use in line assembler if you really want to take control of the chip. There are functions included for I2c, spi, and Dallas 1 wire plus allot of other chips.
I've also used the Netmedia basicx24 with students. It uses an Atmel chip.
The students got up and going faster with the Kronos stuff. Forget the basic stamp. However you might look at their stamps in the class room. They're well done tutorials.