Personal Instance on Personal Computer
First impression I have, if you're needing your laptop for testing code you're running against a full version of SQL 2008, you'd want your laptop running a full version of SQL 2008.

You hit the nail on the head with setting the services to start manually. You could then have a simple .bat file to start and stop the SQL services when needed. This is exactly what I do on my home PC when needing to play with some databases.