Digital transistors look extremely appealing to build discrete logic: They come with integrated resistors so the bias emitter in an RTL gate can be omitted. Furthermore, they are available from many manufacturers in basically any package type, down to chip scale packages, at very lost cost.
There is a nice introduction to digital transistors by Rohm here.
The internal circuit of such a device is shown above. A wide variety of value for R1 and R2 are available. Unfortunately, the minum value for R1 is 1 kOhm, which will already limits switching currents significantly.
Furthermore, although many different variants are listed, not all of those are available. I picked four devices at random from different suppliers.
The candidates are listed above. What is alarming about these devices is that basically no information about transient behavior and switching applications is listed. A few devices liste transistion frequencies, which are rather unimpressive.