A true balanced design might have roughly twice as many parts, but would not consist of two unbalanced units - it would be a different circuit.
First you need to determine what source and load impedances you need it to work with. There are three approaches:
1) one that goes from low impedance to high impedance, like the Fix which iss designed to work with 4K or less source impedance and 100K or greater load impedance.
2) one that works with 600 ohm source and load, the old telephone standard which became the studio standard in the thirties (more or less)
3) one that has a constant impedance so it works with any source or load impedance. These are usually done at either 600 ohms in and out, or 10K ohms. This pretty much requires as many inductors as capacitors, and hence magnetic shielding for the inductors, so it can get expensive quickly.
