Hello,
To assure your absolute satisfaction with your agency's website, I'll gladly provide you a FREE, no-obligation preview on my server.
So first see the results, and then decide if you will hire me.
Joomla will be used, no problem, and I'd propose that we together choose a template that you like and then heavily customize it, to reflect the image of your travel agency. Of course, it's very important for the design to be user friendly, easy to use, mobile and tablet friendly, so I'll give you suggestions in that regard too.
As for the flight and hotel booking and vehicle rentals - do you want this done by connecting to 3rd party websites which provide such services - or do you want your own custom system?
If there's anything else, just let me know.
Best regards,
Viktor