mysql products db design
I am not a database designer.

You don't make dbs but tables.

Both of your table structures can be implemented as innodb tables and as MyIsam tables.

Your first idea is not a good design. It violates first normal form,
so i would propose the second idea with innodb.
the table db1 can be decomposed further in two tables

id | name      | details      | add_date   | brand
1  | some name | some details | 1333128354 | 1
2  | some name | some details | 1333128355 | 1
3  | some name | some details | 1333128357 | 2

id | brand
1  | nike
2  | puma