Played for a few years in jr high/high school and whatnot, went to college and lost interest but here I am wanting to get back to playing. I mainly play hard rock/metal music (rhythm mainly, I am a terrible solo player!) and am trying to decide which guitar I own that I should designate as my D Standard tuned guitar. I have the following:

Fender Strat - standard

Fender Telecaster (custom work) - I had a Seymour Duncan Pro 2 stack put in the bridge and a '72 strat pickup in the neck.

Dean ??? Not sure on the model but it looks kind of like an explorer. Has 2 humbuckers in it.

Ibanez Destroyer (older model, probably 70's) - 2 humbuckers as well.

I know it is pretty limited information but I am looking to play some Gojira type songs and want the best "heavy" sound I can get. Thanks for the help!
After some research, I believe the Dean is the ML79 model. It is the orange/red sunburst coloring. Not sure if that helps out at all. Thanks!
I don't think it matters, but I suspect that either your Dean or Ibanez would sound better (compared to your Fenders). Also, do yourself a favor. Get yourself some Dunlop Heavy Core strings. They have thicker cores, so they won't sound flat-ish or less full of life.

Finally, I recommend using a guitar string tension calculator (simply use google to find one) to find the tension of your current string setup in E standard. Then, increase the string gauges until the tension is almost the same in D standard as it was in E standard. This makes it less likely that you'll need to adjust your truss rod. I still recommend adjust intonation and/or action.