How to launch Photoshop CS5 in either 32 bit or 64 bit mode

Question

Some of my plugins - (notibly Nik Viveza & Silver Effects Pro) only run in 32bit mode at present.   I would rather work in 64bit (I think - hard to tell if I'm getting any real benefit - will have to try some benchmarks)  I work with large files 100mb to 460mb "raw"   which can hit 2-3GB after a bit of photoshop work. 
So - I'd like to have the option of launching Photoshop CS5 in either 64 bit mode or 32 bit mode, without having to drop out to finder to switch the mode back and forth.
I've tried making a copy and setting one to 32 bit mode (so I have Photoshop 64.app and Photoshop 32.app) which sort of works but it requires that I use up the ONE AND ONLY external editor setup  - which makes launching Photomatics, AutoPano Pro, and Helicon Focus a bit more difficult (not that it wasn't already do the the paucity of external editor setups.   It has another issue - every time I change from one to the other something (I suspect OS X 10.6) tells me the path has changed and do I want to update?  I have no idea what that's doing or why.   Another issue is that I get what appear to be random failures to lauch the edit - almost never works if Photoshop isn't running - sometimes doesn't work even if it is.
So:
Lightroom needs more External Editor Setups
Photoshop needs a command line option from Lightroom to launch in 32bit mode or 64bit mode.
Need more reliable launch of editor from Lightroom.
If I'm missing a possible solution please let me know

Answer 1

Vince,
You can have as many External Editors as you want. It isn't very intuitive, but you can hit the Choose button again, choose an application, and then use the "Preset:" dropdown to "Save Current Settings as New Preset..."
All your presets will show up in the "Edit in" context menu.
Hal