Hey Joscow,
Integrateds are usually physically smaller than standalone amps + preamps and the one way in which that usually matters is in the power supply and current delivery. What this means is that they may not drive the most difficult speaker loads as well. Integrateds which double wattage from 8 to 4 Ohms is good, but so is matching them to relatively benign speaker loads.
I personally use one with a separate DAC/streamer specifically so I can swap that out whenever I feel like it. Parasound and Accuphase among others have done a decent job with the built-in DAC's but others like NAD you should listen to them before deciding. I mean, that could be said about anything.
If you decide to get a combination integrated + streamer it's always good to know what the user interface is like and whether it supports your remote devices (Android vs. iPhone).
I use Roon which requires a separate core, but gives me complete device coverage and very nice integration with Qobuz and Tidal and my personal library.