We run a travel site entirely on Wordpress.
What we require is a plugin that will read XML feeds from popular hotel suppliers (Getabed, Hotelbeds etc) and allow us to implement them into our site alongside normal search results, and with landing pages too.
Secondly, we would need a plugin that would allow live booking from within the site itself and implement into a payment gateway (which we already have a contract for) - so users can book hotels within the site.
For more details, use the PMB.