iBook Ram Question

[C Alexander]

Anyone have any input as to particular vendors I should use to upgrade the
ram in my iBook 300-rev B?
I would like to upgrade using a 512 Meg module. BTW-what is the deal with
the vendors mentioning their ram being compatible with the 4.1.7 and 4.1.8
upgrades--is this something I should be aware of--I do eventually plan to
upgrade to X 10.2, etc.
Am currently running 9.2.2.
TIA
ca