The later models (dual core, PCI-E) use a different power layout, and the connector for the front panel is different too.

I'd try your luck first trying to bend out the handle yourself, using something like a steel bar for leverage, rubber mallet. You'll be there all day transferring everything over to a new case, and the risers that hold onto the CPU, motherboard are quite fragile and tend to snap off while you're tearing it down.