Regarding the epigraph package, may I suggest an \epigraphx macro that
adjusts the overall width to the natural text width of the quote, or
maybe to the larger of the quote and the author's name?
Here is what I use myself. (The negative vertical space is owing to my
preferred font setup.)
\newsavebox{\epbox}
\newcommand{\epigraphx}[2]{%
% need minibox for manual line breaks
\sbox{\epbox}{\epigraphsize{}\minibox{#1}}%
\setlength{\epigraphwidth}{\wd\epbox}%
\epigraph{#1\vspace{-4pt}}{#2}\noindent\ignorespaces%
}
From Michael Palmer: