We're just about to celebrate the Feast of All Saints, so this piece showing the Holy Trinity surrounded by Saints filling heaven would be a great addition to your home altar. (Extra points to those of you who can identify any of the Saints pictured.)
If you'd like something that includes purgatory, you might want to try one of these. This one by Giovanni Crespi depicts a soul being released from purgatory because of prayers offered by those on earth. What a beautiful reminder to all of us!
You also might want to consider simply placing family photos on your prayer table as a reminder to pray for the souls of those who have died and to also pray for those still living as you work to finish the race.