I suppose it really depends on what and how you WANT to cook when making a decision like this. Starting out, I’d get me some sort of offset pit with an accessible grill inside the firebox. That way you get the best of both worlds and can take that knowledge without having to spend much. Brinkmann makes an offset that I started on, but my "grilling" or direct heat methods could use some attention. I now have a Gator Bandit and have the grill firebox as well as plenty of smoking, or indirect heating, area.
Live and learn is the best way. You could take my advice and never really know for sure unless you try and fail or succeed yourself.