I have a hunk of 8020 type extrusion (its actually Bosch, but same
concept). What bandsaw blade would you recommend for cutting this.

I currently only have Starrett Bi-Metal Vari 10-14 TPI. Would this be
sufficient or should I go with a finer tooth like a 14-18.

I only need to make 1 cut, but would prefer the bandsaw to hand as I'm
not very good with a hacksaw (you should see the junk job I did on the
wire closet rack I just cut by hand).

I would also of course prefer to not wreck my blade Best to buy a
new one if needed and have 2 than buy a new one to replace the ruined
one.