I had an Android phone which I eventually was able to root/mod; here's some advice, for what it's worth:
- Get a device which has a supported root/mod path via XDA. Some devices are more rootable than others.
- Be careful about updates; most root tools only work for specific versions, and patches regularly break rooting methods/scripts.
- If you want to preserve root, you'll want to run a cusom ROM, so find a device which has a supported mainstream ROM for it.
- Unless you are an expert, it will take a while. Plan on spending at least a week of off/on time messing with it, and be prepared if you brick it.
- If you want full control of the device, plan to make this your full-time job. Nobody really offers this, and you'll need to do it yourself.
- If you just want something with reasonable privacy controls which just works, get an IOS device; that's what I did eventually.
Also, as a side note:
- The regular web does suck, and browsing without an ad blocker these days is pretty horrible. Mainly posting to say that.