The maximum you will get is a 1 year visa that too will depend on the embassy you are applying. Also it cannot extend beyond your UK Visa. I was living on Tier 1 and had applied for Schengen twice. The first time I got it for 1 year from the Czech embassy. The next time was just for the duration of the trip (2 weeks) when I applied to the Spanish embassy. Bear in mind that I had 6 Schengen visas already and that helped getting the 1 year visa.
Good trick is to mention that you will be traveling to Schengen states for the next 1 year and give a detailed itinerary for the office to believe you. You might not have tickets for your travels 8 months down the line but mention what are your plans. The cover letter should be convincing.