The Kilauea is a 1997 size 17, the Fire Mountain is a 1999 size 14, the C16R is I think a 1996 and definitely size 17.
On eBay, the Kilauea might make £250 (was £1,000 new), the Fire Mountain £125 (was £450 new) and the C16R £100-125 (was c£600 new). If anything, they might go higher in each case, as female owners keep their bikes in a much better state than males, and are far better to buy from. Of the three, the C16R is the most undervalued by the eBay market, and therefore logically perhaps the one it would be most sensible to keep. Although obviously you will keep the one you like the best.
The C16R might be slightly the most difficult to 'do up', as it as a 1" head tube and geometry for a short fork, so it would be slightly more difficult (but by no means impossible) to find a suitable fork for it.