I'm an Asia noob but I just got back from visiting Cebu for a few months, then Cagayan de Oro for a month, then Manila for just a few days.
Since I don't have a ton of experience, I can't say whether PH is the best country for you, or where is best in the Philippines, however, since you mention internet, I presume that means you will be working? Because I think if you're going to be working weird hours (late into the night or even all night if you're working US hours), the best choice is IT Park in Cebu. Reason being, there are tons of places open 24 hours so you can get coffee any time of night, go to a restaurant, or go to 7-eleven for a few groceries (but you'll probably also have to go to a bigger grocery store before it closes at around 9 PM.)
Cebu seems to have tons of expats, however, I didn't notice what I'm used to in Latin America, where there will be a tight knit community of expats who are often living there long term. One thing you should be aware is that foreigners don't always have the best reputation in PH, part of the reason probably being how easy it is to stay there without a visa.
Re: Manila, I was in BGC and I think there are also enough 24 hour places if that's necessary for you. I think Manila is generally a cooler city than Cebu, however, the traffic is horrible, good luck even catching taxi or Grab (local ride sharing app) at certain times of day.
Cagayan de Oro is sort of random, I went there because my buddy's wife lives there. Was actually my favorite, but definitely not terribly developed / lacking in infrastructure. Generally you'll experience a more laid back vibe in the smaller cities in the Philippines which personally I like more. And if you stay near a major mall, everything will be walking distance, which is nice.
Not familiar with other options besides AirBnB, I'd ask around more or maybe try Facebook marketplace. But I'll say the quality on AirBnB is quite poor and without the protections of a third party like AirBnB, your experience might even worse.
Overall I'm super happy I visited PH but I said I'm an Asia noob... I don't have other countries in Asia to compare it to. Personally I think of the more affordable Asian countries, it's the best choice for me, but I'd also like to try one of the more expensive countries sometime.