Either rim size will be fine for recreational riding.
You will have more tire options with the 26" although available, the narrow high pressure selection is small. With the 700c, the wider low pressure selection is small. But frankly, either rim size will do fine. If you plan on more road/path type riding, I'd recommend the 700c. It will "roll" a little better than the 26". The 26" would likely be a more durable wheel in that it would handle pot holes and such better. A well built 700c is by no means unreliable.