Get a carbon 300cm probe if you are worried about the weight. If the shit hits the fan the longer probe isn't always about depth. If you have a 240 cm probe and your victim is buried say around 200 centimeters. When you are probing, it is a lot more work to probe all the way down. You're bending over much more and such. With a 300 centimeter probe it's just a little easier. It's not necessary, a 240 will work, just a thought for you. As far as deploying goes. If you are having problems deploying your probe, you need to practice with it more. Regardless of length.
For the shovel, make sure you are rocking a metal blade.
Being that I am in Colorado and we have a continental snow pack, I used a 240 cm probe for years. Now that I am traveling to Maritime snow pack locations at least once a season, I'm rocking a 340 cm carbon probe. Did some snow pit stuff and that probe got swallowed when trying to measure the snow depth. I had my arm in the snow up to my shoulder and still couldn't hit ground. In an avalanche situation and a deep snow pack like that. Yeah, a longer probe is a great idea.