Tosca is seasonal colour and will not be available in future.
BJ is classic colour and available all the time. I like BJ very much.
This colour can be used for the whole year (including summer - match with white colour, winter - match with black colour).
If I were you, I will buy Tosca Lindy first and later buy BJ Lindy.
U may regret if u let go of it now!!!! It's v nice and I m pretty sure u will get other color of lindy later on! As u always say, ' this is my last H bag etc etc'