I think given proper input this could be a stickied thread...
I mean until you have done it, you are really just going through a guessing game... so a pros/cons/photo thread would be helpful to some...
I'll see if I can't get a photo this weekend... wait for a post edit....
---as for the 1JZ move the firewall hole to the driverside, well I did this, and sure it reached - after I custom fabbed some ECU brackets which rotated it 180, and I still needed an intermediary harness for the dash/chassis plugs... (fortunate to have a 1/2cut and a full parts car.) that area becomes tight quick - heater hose, throttle cable, brake lines, vac hoses...
---12V fuel pump mod helps clean up the passenger strut tower...
---by de looming the harness a little I managed to get the ignitor(+DLI) and injector moduale into the dash (I know my timing loop is now in there - probably a PITA later)
---Cruise control can be deleted and plugs pulled back into the drivers fender
---some people even move the fuse box - a little impracticle in my opinion - to inside the fender splash guard...
---battery relocate -- personal taste.... I passed in favour of a second battery...