If I want to keep bm in deep freezer, do I freeze straight in the deep freezer or do I freeze in refrigerator freezer first and transfer over?

Straight into the deep freezer will do. Fresh milk may be placed in a separate deep freeze (chest-type freezer) for 6-12 months. Milk can sometimes be stored even longer if it is immediately frozen and is frozen at the lowest possible temperature (-20 degrees). If previously kept at room temperature, or stored in a cooler or refrigerator before freezing, storage time may vary. Deep freezing is best.

Its best to directly keep them in the freezer but there are times when the fresh breastmilk in refrigerator is unused( as baby dont drink finish those I've set aside),I put them into the freezer after 3days. Still good for me!

Any suggestion of brand for deep freezer? And the capacity as well?

Straight in deep freeze is better. Less temperature fluctuations.

Keep them straight in the freezer.

Straight in deep freezer