Christ is risen!
When one misses liturgy, how many kathismata should he pray? Are there any in particular that he should pray or can he choose whichever?
Whenever we cannot attend the Divine Liturgy, my husband and I chant/pray the Reader's Typica. We chant the appropriate troparia and kontakia, and we also include the readings from the Bible. One can also pray the Divine Liturgy, but then substitute "Lord have mercy, Lord have mercy, Lord have mercy" for any priestly prayers of the Holy Service.
Praying the Kathismata is lovely, usually three are recommended, but one does not get the sense of the Liturgical cycle. If one is stranded without a Bible, then reciting the Jesus Prayer is also recommended. A priest told me that reciting the Jesus Prayer 300 times is appropriate. This I did while in the hospital with pneumonia on Pascha years ago. I could not sleep due to all the beeping monitors anyway, so I timed the Jesus Prayer to the beat of those monitors.