Those EUR5 LA's are a great way to start with LA use. In my opinion, they should be a part of each and every "arduino starts kit". I have used one for years with Sigrok / Pulseview. It's very sad and unfortunate not much work is being done on the Sigrok project anymore.
About half a year ago I bought a Kingst LA2016, because I wanted a bit more speed and channels. I verified that the software works on my Linux box (Other OS-es are apparently also supported). LA2016 also works with Sigrok/Pulseview if you install one of the latest unstable versions.
I have not yet really used my Kingst LA2016 for a project, but overall I prefer Pulseview over the original software. Pulseview has a whole lot of decoders (about 100+) and you can also write your own in Python. (those decoders are slow though).
I bought the Kingst because it was mentioned on the Sigrok site. I would love to buy officially supported hardware from Sigrok itself, but unfortunately there is none.
Bostonman suggests buying the LA5016 instead, but it's significantly more expensive. It's getting into a price range when you only buy stuff when you really need it. Even though I bought the 2016 myself, I still recommend to start with the EUR5 boxes. They cost just lunch money, and they are much more then a toy.
For sample rates, you want your LA to sample at least at 4x the data rate, but often you want more. You don't only want to capture the data, but when you want to do time measurements and delays between signals, you need a higher resolution. For example when you want to measure the propagation delay of a simple inverter, you can't do much with a LA that samples on only 100MHz. But capturing accurate data at those higher sample rates is also not trivial.