This is an alternative reference for Thalberg's Op. 44, reflecting the popularity of opera transcriptions in the Romantic era. It displays the characteristic grandeur and complex textures required by the composer's pianism.
Practice the rapid arpeggiation patterns to ensure fluid transitions between chords.
Comparable difficulty and character — good candidates for what to learn next.
Andante final from Donizetti's 'Lucia de Lammermoor' Op.44 is rated Henle level 7 of 9 — late advanced repertoire, roughly ABRSM grade 8 and above. In the RCM system it corresponds to about level 9.
You should be comfortable at Henle level 7 — meaning you can already play level 6–7 pieces cleanly. Learning it one level early is possible as a stretch piece, but more than that usually leads to months of frustration.
A typical performance of Andante final from Donizetti's 'Lucia de Lammermoor' Op.44 lasts about 7 minutes.
Andante final from Donizetti's 'Lucia de Lammermoor' Op.44 is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.
Pieces at a comparable difficulty and character include Andante final de 'Lucia di Lammermoor' by Sigismond Thalberg, Ballade by Sigismond Thalberg, Ballade Célèbre by Sigismond Thalberg — see the full similar-pieces list on this page.