I have a traxxas summit with a tekin t8 1900kv and a traxxas slash 4x4 with a 3800kv castle creations. I just have them for bashing and don't race. The summit is the 775 brushed i bought the tekin for. The slash is a vxl but cogs with the castle on the vxl-3. Put the velineon back on and its fine. I've had rc's for awhile but have never upgraded esc so im pretty much a newbie at it. I was looking at the hobbyking speed controllers and needing some advice on which is best and what size is needed for the 2 trucks.

Do you run in the water? If not, the Xerun 150A is a great basher esc for the summit with that T8 motor. For the Slash I'd run a Castle MMP and then upgrade to a sensored motor for it later on.

I will be taking it in some water if the t8 can take it but not submerging it. I also have a turnigy trackstar 5.5t for the slash so I would need an esc that would work both

I have a Hobbywing SC8 waterproof esc in myTelluride with a 4000kv Toro 550 motor and it does well. I've had it under water a few times when I didn't get the waterskip right. This esc isn't sensored though.

I think you have to use conformal coating on the board in the T8 to protect it and you would have to do the same with the Xerun esc too. Use a Dielectric grease on the sensor wire port to help there. Not sure if you are on RC Crawler or not but they have a lot of info on waterproofing electronics there.

I think I saw John Holmes from Holmes hobby say he can waterproof anything so you may want to get in touch with him on exactly what to put in there.