Electronic – Best way of switching between different resistor/capacitor values in a layout

It's not clear what exactly you mean by series versus parallel resistor-capacitor filters. Posting a schematic of each would clarify this.

You probably mean series is something the signal passes thru, and parallel is something that works as a shunt. Note that the same thing that is a low pass filter in series is a high pass filter as a shunt, and vice versa.

Basically a capacitor will block low frequencies and short high ones. If you put it in series with a signal then it is a high pass filter. If you put it accross a signal, it will short the high frequencies thereby making a low pass filter. The value of the capacitance and the resistance it is working against tell you the -3dB rolloff frequency of the filter, whether high pass or low pass. This frequency is:

\$ f = \dfrac{1}{2 \cdot \pi \cdot R \cdot C} \$

When R is in Ohms and C in Farads, then f is in Hertz.

You're off to a good start. Yes, you can buy three resistors and wire them in series (not parallel!), although the first resistor you link to is a 22k, rather than a 2.2k, and if you connect the three resistors you've chosen, you'll get 34 k, rather than 14.2 k.

Despite the fact that they seem flimsy, the units you show will handle at least 100 times the power you expect to dissipate. After all, your calculator (correctly) showed that the desired resistor will need to handle .0018 watts, and each of your examples will handle 0.6 watts.

Finally, you really ought to be able to find a single 14k resistor to do the job, and you can forget building up combinations. Use this link http://www.daycounter.com/Calculators/Standard-Resistor-Value-Calculator2.phtml to determine that you can use a 14.3 k, 1% resistor and save yourself some effort.

And finally, finally, I'd recommend you stay away from Maplin. They have no search ability whatsoever, and this will make your attempts at finding appropriate parts a misery. As an alternative, try Digikey. I'm sure there are other suppliers in the UK as well, but that is one of the convenient go-to sources for parts in the US, and their website indicates they have facilities in the UK.