E90 320D 2005 Cat removal

Hi Guys

need some advise about cat removal.
my beloved tractor currently has 104k on the clock
I heard from some dudes on the forum that 100k
is ok to remove the cats.

I am hoping to get improved performance and economy.
would this conversion help. I am in cape Town, anybody able to recommend a fitment centre where they had theirs removed and the cost of the job?

Also, would a software upgrade help?
How would I check what version is currently installed and
which version is the latest.