Which Road Bike for Triathlon Training: Aeroad or Ultimate?

Hello everyone,
I’m interested in buying a new road bike and I’d like your help in understanding which option would be the best fit for my needs.

At the moment, I’m riding my old road bike with a 10-speed mechanical groupset for flat and mountain rides. However, my new goal is to start doing triathlon — specifically, to complete an Ironman 70.3 next year, not competitively but purely for personal satisfaction. So, I’m looking for a new bike that can replace my current one and also serve as a solid training bike for this goal. That said, since I’m still new to triathlon and unsure if I’ll continue with it long-term, I’m not considering buying a dedicated triathlon bike just yet.

Right now, I’m undecided between the Ultimate and the Aeroad. The Aeroad, being more aerodynamic, would be closer to a triathlon bike. On the other hand, I often ride in the mountains and I’m worried it might not be the best choice for climbing, which is why I’m also considering the Ultimate. In both cases, I would combine the bike with the “GEAR GROOVE Aero Extensions.”

Since this will be a bike I plan to keep for many years, my idea for both models was to get a good frame with an “entry-level” groupset and then eventually consider possible upgrades later on.

For the Aeroad, I was considering:
– Aeroad CF SLX 7 AXS SPEED – https://www.canyon.com/it-it/bici-da-strada/bici-aero/aeroad/aeroad-cf-slx/aeroad-cf-slx-7-axs-speed/4035.html?dwvar_4035_pv_rahmenfarbe=R107_P04

As for the Ultimate, it doesn’t seem like there’s a CF SLX frame with a basic groupset, and I found these two models:
– Ultimate CF SLX 8 AXS – https://www.canyon.com/it-it/bici-da-strada/bici-gara/ultimate/cf-slx/ultimate-cf-slx-8-axs/4067.html?dwvar_4067_pv_rahmenfarbe=R100_P08
– Ultimate CF 7 Di2 AERO – https://www.canyon.com/it-it/bici-da-strada/bici-gara/ultimate/cf-sl/ultimate-cf-7-di2-aero/4248.html?dwvar_4248_pv_rahmenfarbe=R101_P06
I’m not very knowledgeable about this, but is there a big difference between the two types of frames?

Thanks in advance for your answers.