The Slash 4x4 should be able to be tuned with a much stiffer suspension and still get traction thanks to the 4WD, so it will be able to actually handle quite very differently from the Slash 2WD-inspired, big body roll Strike. To use stick packs and get 4WD, I don't think you'll find a better for-fun platform than the Slash 4WD. You can put a buggy body on it if you want it to seem a lot different. The problem with the 4WD 1/10th scale space right now is that most of the vehicles are either racing machines (some requiring saddle packs) with low ground clearance and precision handling (and big prices) or entry-level bashers that won't handle a lot of power.
If you really want to try a pure buggy though, I would recommend the Tamiya Durga or Baldre (same car different body). It's a low-end version of their racing buggy and is fairly durable and accepts regular packs.