What would be the best code to have two bits of text in a single paragraph, one left aligned, the other right aligned, that also is:
The only half-way proper way to do this is
Text on the right
Text on the left
however, this will get you into trouble if the text overflows. If you can, use divs (block level elements) and give them a fixed width.
A table (or a number of divs with the according display: table / table-row / table-cell properties) would in fact be the safest solution for this - it will be impossible to break, even if you have lots of difficult content.