Here's a picture of V1!
I've been working on a ~1kW adjustable load for work, because I'm doing a lot of PSU design, and it's getting awkward testing them. You can buy a big high power resistor, but they're ~£100 a...
BriCom'sp suggestion of a buffer chip would work just fine, or the simplest thing would be to use a MOSFET. Assuming you're using this for some kind of slow switching rather than signalling.
Referring to the pins as...