wXR
Good luck to you mate
only thing I'm not sure about is the removal of the floppy drive... doesn't the Amiga look for a DF0 before it will start ?
Anyways having already spent more than I anticipated (Accelerator Card, Indivision, IDEfix etc) I can only say "I hope you have deep pockets"
I don't see the point of USB on a 1200... the PCMCIA adapter for CF and/or card of your choice is more than adequate for file transfer requirements... USB keyboards.. ok but whats the point if you are leaving it n the desktop case ? Pen drives? thats showing off.... there ain't no way you will generate a 2 gig File... and forget about transfer speeds... but if you must you must.
With what you plan as others have said, I'd go the tower route. My 1200 gets warm and it ONLY has the Indy and an 030 Accelerator - I run with the trapdoor off. There really aint much space for cooling unless you start butchering the case, (fugliness warning, and yes most hack jobs on A1200's are, with a few exceptions) Fans will also be noisy.....
Not trying to put you off, not at all, just that I have absolutely no idea what you would use such a machine for (watching the "latest" 8 year old '060 'demo' perhaps ?) but as I say... it will be interesting to see how you get on
Andrew