Choices!

So I have a 15" 2010 MBP that I use for my main computer, and I love it very much. So much, in fact, that I have started worrying about taking it out and about to work with me every day (I work on an ambulance and use my computer to enter patient care reports) I am scared to leave it on the ambulance - people like to jank stuff out of ambulances since they have nice things like drugs and expensive equipment inside. Also I'm scared I might drop it, or that someone could spill something on it at the office! You can't be too paranoid about these things, paramedics can be pretty clumsy and I I don't have 2000 dollars to buy another one, ha! Anywho, I am looking for a cheap Apple notebook to use for work purposes (and maybe some light schoolwork as well for when I'm not at home) and there is a local computer place that deals with used refurbished Apple stuff on the cheap. My choices are a C2D 1st gen macbook (black or white) completely tricked out for $550, or a maxed out iBook G4 for 250. I know the G4 was a good computer in its day, but I'm relatively new to Macs, def wasn't using them in the PPC days...should I go with the cheaper buy? In theory the iBook can do everything I want it to (surf the net, email, word processing, etc.) But I know if I got the Macbook I could put Snow Leopard (and Lion) on it...decisions decisions.