New dev looking for suggestions on computer setup!

Hey guys, first time posting here. Hope I don't bother anyone by putting my question here, but I really wanted to ask a community of software developers. If this needs to be moved somewhere, please let me know and I will promptly do so.

I have a software development gig where I'll be developing some software written in Python. This job will also require software demonstration for the client, while traveling.

With that being said, I am buying/building a new computer setup that will be secure and generally air-gapped for security reasons. The software functionality is highly recursive numerical simulation.

My question: is it possible and feasible to buy a singular laptop that is light and portable that also has enough under the hood to do the development on and also travel with?

Part of me is considering building a development-focused secure PC in addition to getting a laptop that will be solely used for demonstration purposes and travel.

I would truly appreciate the feedback from you guys considering a majority of you are likely considerably more seasoned software developers than I and it would be a great help.

Best regards,

-~§InfiniteCuriousity§~-