iMac G3 with G4 processor upgrade?

[Tiernan O'Toole]

right. i have an iMac G3 333 (Rev D) with 288mb ram and a 6gb hard drive. i have OSX 10.3. im upgrading in the next few weeks, starting with an 80gb hdd. im going to add an extra 256mb ram bringing it to 512mb, and then finally im looking at a processor upgrade. i found this upgrade [http://www.technowarehousellc.com/imacg4upgrades.html] and im looking at getting it. has any one tried one of these? is there anything i should know about them? will it be as fast as a standard G4 466 or is there going to be a major speed difference? i was told Panther will run on it, so im guessing it will. also, on a slightly different note, im thinking of putting the parts in the current imac into a ATX case. mainly because my monitor on the mac is dying, but also because i can get more stuff into the ATX Case (have a CDR drive as a slave to the hard drive and keep my standard CDRom drive working too). has anyone tried this, and if so, any tips? 
Thanks in advance.
Lotas T Smartman, MCP
www.lotas-smartman.net
www.the-hairy-one.com
www.lsn-blog.tk