Many of the SiLabs chips are NOT standard 805x-types, so be sure to read the datasheets when you pick one.

Further, if you to witn one of the fast ones, i.e. one that has an internal clock faster than, say, 10 MHz, you can start to worry about crosstalk between signals due to the very fast rise times and the typically 5 pF or more capacitance between adjacent terminals on the "breadboard." The CMOS inputs and outputs are very high and low impedance, respectively, so the high-impedance input "hears" the energy in the low-impedance output. There's not much you can do about that.

Down around 1 MHz, as in the classic 12-clocker, it's not so bad.

The most important thing about "solderless breadboards" is that they may work today and refuse tomorrow, since the connections, on their very best day, are poor at best.

RE