Upgrading a PVR / DVD-R

I have a Panasonic DVD recorder with a built-in 40Gb hard drive. I've opened it up and it looks like a regular 40Gb IDE hard drive. I was thinking that I could upgrade this myself using some hard drive duplicating software. Will that work? Has anyone tried this? Or do you recommend going with a company that specializes in doing this?

Since this may require a firmware upgrade I am thinking that I better let someone else do this. If so, are there any companies that you could recommend?

If so, replacing hard drives couldn't be easier. Here's one of several companies that will help:

http://www.weaknees.com/

If it's not a Tivo, the hard drive is still going to be a standard ide drive. The trick will be finding out what software you'll need to prep the new drive. I'd google "[brand of your pvr] upgrade hard drive" You'll almost certainly find good instruction, downloads and help.

Weaknees only does Tivo-based systems. Mine is a stand-alone unit w/o the Tivo-type subcription system. Any other companies that come well recommended?