8-bit tristate logic gates
I am not sure if such gates comprising of 8 logical elements ever exist. Imagine, if you have 8 two-input one-output gates in single chip, this chip must have 2*8+8 -> 24 logic pins plus two power pins, thus at least 26 pins.

If such devices ever existed, they must be custom and special for some kind of old computer.

Such logical operations are usually done within microprocessor/controller within ALU, and inputs and outputs are managed internally to the device.

I think you wanted to ask something else, closer to the real thing you want to achieve.

But in general, the ways you may consider implementation of such logic are:


Use CPLD/FPGA:


pros: small footprint, very quick in terms of latency;
cons: price overhead to implement such simple logic;

use smaller PAL/GAL or other older PLD chip less in size than CPLD:


pros: medium footprint, simple to wire;
cons: it is a question if this will cost less than modern CPLD;

use pre-programmed ROM with 16-bit address bus and 8-bit output data. This ROM will have output byte programmed for respective address (8 bits for operand A and 8 bits for operand B). ROM chips do usually have chip select signals, thus you may have tri-state output when chip is not selected:


pros: medium footprint, low cost;
cons: ROMs, depending on type, may have latency up to tens of nanoseconds; will need proper ROM image to be developed.

use MCU:


pros: very cheap, small board footprint;
cons: requires firmware and proper design of the internal program to keep latency predictable.

if you want to use simple glue logic then you must take 2 NAND chips (for example for NAND operation - 74xx00) and then use 74xx125 type buffer chip (or equivalent):


pros: low cost (questionable), circuit and board are visually comprehensive (e.g. for education);
cons: large footprint.