Flush mount vs fairing block ducer 28 footer

[Overtime Fishing]

Upgrading electronics and have a question for the local pros. I am going with 2 Simrad Nss8s on a 28' Henriques. Putting a new transducer on a as well, 1kw 50/200. Only question is whether should get the ducer in a fairing block or can I get away with a flush mount? I was sold on the block but the guy selling it to me said to go with a bronze flush mount. I am cruising around 21 knots and might make 5 Canyon trips a year give or take. Appreciate any insight, if this is posted in the wrong board my apologies, just redirect me to the the right one.

Thanks,
Doug