There aren't than many different types of overdrives. Most are either based on the Tube Screamer (ie. BOSS SD-1), Blues Breaker (ie. King of Tone), or Klon (ie. Soul Food). There aren't that many different circuits, the main difference between the "basic" pedal and all of the boutique clones and variants are a few component differences, different clipping diodes, or added tone stacks. The AC/RC Boost pedals are basically a tube screamer clipping section with an added bandaxall tone section instead of the simple high cut in a standard Tube Screamer. There are some boutique pedals that are mashups of two designs (ie. Timmy and Tim).
For the "tightest" pedals - you want something with a good amount of bass cut - cutting bass is what creates the tight sound. Basically, anything with a bass knob should allow you to dial in a tight sound.
The other option is a distortion pedal, with the gain off. I've had really good results with the Suhr Riot pedal as a boost.
For the pedals you mention -
The Grind is based of the TC Electronic Integrated Preamp, which is what Meshuggah used on their early albums to boost and tighten up their amps. The TC has bass, treble and volume boost. The Grind takes the bass value setting that Meshuggah used, and sets that as a permanent value. It essentially gently rolls off everything below 1k, which will tighten up the tone for sure. The Grind will be different from your current OD, because it doesn't have a diode clipping section, it's purely a voltage boost and EQ.
The Grid Slammer is a Tube Screamer clone with a slightly different clipping section (it copies the Landgraff Dynamic Overdrive). If you want to get your gain from the pedal, then the Grid Slammer will be a little different than your current OD. If you run the OD pedal with the gain down and the volume up to boost the front end of the amp, the Grid Slammer will be very similar to your current OD.