You read my mind leh! Oh, no worries about the cosmetics as that
has been taken care of. Yes, I'm hoping at someone who can insert a
Internet Bank Transfer module in ZC. I think it's better with that
sorta functions integrated within. This is solely for Singaporeans
who prefer IB than Paypal.'
Are you doing for a fee or for leisure nia? 
I'm doing this for a living actually ... 
but you give me the specs and I'll tell you if it's possible or
not lah ...
I worked on some other third party payment modules on zen-cart
before ... things i'm not going to put up on their download page
....
I got to warn you though, because of the way the database and
orders processing is set up in the system, I'd have to mess around
and set up more tables in the database etc, which would make
upgrading to future versions a bit more painful ...