Lintel end bearings

What is the recommended end bearing for a 900mm door and a 2085mm garage door that is only single-story and will have 2 courses of block above it, and a flat roof (8x3 joists, 18mm OSB3, and EPDM).

I have read that I will need a min bearing of 150mm but I am not sure how to apply that since I am dealing with two vastly different lintel sizes. Also, since this is a single skin garage, I will be integrating piers for both doors to add more stability, so I will probably need to use steel lintels, unless you can get 200mm wide concrete lintels.

On my build it was 150mm min on both back door and french door lintels.

My lintels were steel just the 2.4 one had to be a heavy duty.
My spec says:
Minimum end bearing for all lintels to be 150mm (end bearing may be reduced to 100mm where span is less than 1.0m).

It should tell you in your building spec recommendations for lintels and bearings.

Your post is a little misleading I'm afraid. You are talking about 2 different size lintels, so the 2085 garage door is at the front, and the 900mm door will be at the side, or the rear. With an opening of 2085, you'll need a 2385 lintel (go for a 2.4m) to span the gap, and have it supported a minumum of 150mm either side of the opening. So you'll need a pier at either side of the opening to give you stability, but you don't need more than a 100mm wide concrete lintel, and you'll then cut the bricks to cover/butt up to the end of the lintel as you go round the corner. As Morpheus says, for the door, you only need a 100mm support either side of it, so an 1100 is sufficient, but just go for the 1200 for simplicity.