Problem Trying to get Outlook 2000 running

Hi Guys

Just been asked my manager to look into setting our Outlook 2000 running.
I'll explain it the best I can with the knowledge I have.

We use Outlook 2000 and all was going well.
We then decided to switch everything to google (gmail etc)
While this was going on as a 'stop gap' we began using Thunderbird.

Now we have "Double Delivery" issues affecting not only us but our customers.

Is there away to get Outlook 2000 synched with Google Mail including calenders,contacts and tasks etc.

I have come across 02g but we would prefer a free option.

Any Help or Guidance is greatly appreciated.