It seems you are not aware of Yann's Bitwise Operations plugin?
It covers binary numbers and bitwise operations.
There's no hex plugin as far as I know, but you can create your own hex strings. Create an array with strings "0", "1", "2", ... "9", "A", "B", ..., "F"
For the conversion, use division, modulo, etc. For example, the number 31 would be "1F" as hex string. You'd get that result by int-dividing and subtracting:
firstdigit = int(number / 16) = 1
seconddigit = number - firstdigit * 16 = 15
Now just look at array(digits + 1) to compose your hex string:
myHex = array(firstdigit + 1) & array(seconddigit + 1) = "1F"
It's a very simple example, for 4-byte values it is a lot more dividing, subtracting, modulo, etc. And I'm not sure if it makes sense to convert them, but at least that's the principle.