I have tier 1 work permit. Need to get Schengan visa.....

Hi All,
I recently moved to UK from India on Tier 1 work permit. I'm an Indian passport holder.

I got offer with a company that I was working for when I was in USA. The same company has a registered office in UK too. But the company wants me to make frequent visits to their client places across European countries. I would have to mostly travel to Germany and Switzerland.

I'm looking for the following information:-
1. I should be able to vist any European country, any time, for the next 3 years. What visa will help me in this case? Schengan?
2. If Schengan, what kind of schengan visa I should apply for?
3. What are the documents I need to submit
4. How long would it take to obtain the required visa?
5. Which embassy I should apply the visa with?

Most of our clients are in Germany now. Wondering if I re-locate to Germany would hep me to get a visa that will help me to travel around Europe without any restrictions for next 3 years

Every one of my client visit will be for 3-10 days.

I came to UK on work permit because my company has registered office only in UK but I'm kind of stuck as I could not travel to any of our client's place outside UK

Please help/suggest what is the best solution in this case. Thanks a bunch in advance.

-babu