Ignorance-Choosing tecnologies

Hi people, I need some pointers in the right direction as to choose the appropriate technologies for the job.
Being a C,C++ fan, I have never been comfortable with java and friends, neither web development, and well,
my ignorance is huge. I really hope this is the right forum for this post. My apologies if it is not.

I've just had a meeting with a corporate customer of mine who wants to homologize several systems into a common
corporate-wide architecture and he strongly spoke of "light clients, powerfull servers, html and java".
It sounded to me as a thin client architecture, application servers, web servers and database servers. Citrix seems
also to be part of the equation. I know this might sound misterious but that's my customer, misterious.

Now I need to implement a couple of new systems and I would like my initial propposal to go along the line of his
long, middle term objectives. Servers are mainly Unix, Linux boxes. Windows clients.

Any comments that might point me into the selection of right technologies for these developments would be
greately appreciated.

Thanks in advance.