there is a used Boss BR600 on luther's classified ads that should meet your requirements,
and its a multitrack, so it should meet your future requirements too.
Just to expand
It is all in one, has stereo condenser mics, has built in mixer, has built in recorder
and built in drum machine
the learning curve when you start off will be harder then just a normal straight recorder
but its not too difficult.
You can download the manuals of boss website to see if it suits your requirements.