How to achieve similar configuration across different archs?

[Itay <debian@itayf.fastmail.fm>]

Hi,

After working for few months with debian on my home desktop I feel 
ready to move my work desktop and laptop to debian, too.  (From RH 
based installation, in case you ask... ;-)

My home desktop: 64 bit dual core CPU but runs i686 kernel.
Laptop:          32 bit CPU.
Work dekstop:    64 bit quad core CPU, 3GB DDR3 mem.

I want the 3 machines to 'look' the same as much as possible.
I am aware that many setting I will have to admin manually and
   separately on each machine.

However, I'd like to minimize the work in 'sharing' my setting.
So -

1. To achieve similar package selection I am going to use
     dpkg --get-selection
     dpkg --set-selection
   Are there any pitfalls in doing so?
   (Incidently, is there a way to do this using aptitude?)
2. Are there other configuration setting that I could
   'share' in an automated way?
3. I  was going to install an amd64 kernel on the work desktop.
   Any pitfalls there?

Thanks in advance for your help,
Itay