Get a 300 / 320 cm probe. Honestly, the extra 80cm (or so) is well worth it.
I have never been in a situation where I have said, dam my probe is too long. However I have been in situations where probes have been too short.
the additional size and weight are negligible.
I use an Aluminum G3 probe, works great. Just be sure to familiarize yourself with your equipment before heading out. Probes are pretty straightforward, but each lock in place just slightly differently.
I would suggest Al over carbon, only because I use my probes to isolate my test pits with a rutschblock cord... and I Would want to be dragging a rutschblock cord over carbon too many times.