I want to replace them all if possible but if the low energy
ones are too tall they will look silly.

My experience of candle shaped low energy bulbs is that there is still a way
to go on sizes. I can't speak for the screwfix ones in particular, but the
GE ones, which are good make, would look OK in a chandalier, but hopeless on
a small light fitting. If you wait long enough, there might be LED types
that could do the trick.

Christian.