Why stranded since once laid, no movement. But, if stranded is a must, All Electronics has a good selection at a decent price -- and I like 26AWG:
Solid wire has very little advantage.
Small nicks in a conductor can weaken the physical strength of that conductor and is almost always where breaks occur.
After many years of working with and designing electronic equipment I follow one major design rule when it comes to circuit wiring. Use stranded wire in all harnesses and for circuit connections.
Stranded wires are forgiving as the individual stands, being of small gauge, resist breakage.
Losing one or two strands doesn't usually compromise a wire's strength.
With proper tools, you can strip stranded wires as easily as solid wires.
Properly tinning stranded wires is an easy task and helps in the final soldering of a circuit connection.
Three caveats: I use both tinned stranded and solid wire in a solder-less breadboard. When it comes to wire wrapping, solid wire is used. When it comes time to repair circuit board traces or add modifications, solid wire such as #30 AWG wire wrap wire is used.
But, you can stick with solid wire if needed, be aware there may be some wire breakage especially if things are moved.