Edward Feustel wrote:
I am interested in opinions on whether it would be better for me
to use a 450 or 600 ohm balun that might more closely match the
transmission line (in practice).

450/50 = 9:1, 600/50 = 12:1 - Is that what you are thinking?

On a transmission line with standing waves, the impedance seen
by the balun will NEVER be the Z0 of the transmission line.

Let's say you are using Z0=600 ohm feedline with an SWR of 20:1.
Let's say a current maximum point exists at the balun. The balun
will see an impedance of 600/20 = 30 ohms.

Do you want to use a 4:1 balun and take it down to 7.5 ohms? Why?
Do you want to use a 9:1 balun and take it down to 3.3 ohms? Why?
Do you want to use a 12:1 balun and take it down to 2.5 ohms? Why?

Do you want to use a 1:1 balun and leave it at 30 ohms?

When the impedance being encountered by the balun is unknown,
a lot of experts recommend a 1:1 current-choke-balun.
--
73, Cecil http://www.w5dxp.com