ILR eligibility for WP+ICT

Can someone help me with my ILR eligibility scenario.

I came into the UK on the 3rd Feb 2006 working for an Indian company, on deputation here. I will be completing 5 years this months and need advice with the ILR application and eligibility. My visa history is as follows:

- The first visa was a Work Permit for 2 years from the 20/01/2006 - 20/01/08
- Following which the same company applied for a Work Permit extension for 18 months, which took me until 20/07/2009. [Total stay of 3.5 years]
- After this i had a further extension for 1 year, which was a Tier2-ICT (under the transitional arrangements of the PBS). [Total stay of 4.5 years]
- After this i had a further extension of 1 year as a Tier2-ICT under the established staff category, with a biometric permit (ICFN) which is valid till the 20/07/2011 [Which will take me to a total stay of 5.5 years]

Can you tell me if i am:
1. Eligible to apply for my ILR under the Tier2 transitional arrangements in place
2. Can i apply using the premium service, at one of the PEO
3. Would i be better of applying via a consultant like yourself, or should i apply myself.