The American singer Sandi Patty released over 30 albums so far. Some of the albums are Sandi Patty ‰ÛÒ For My Friends (1978), An American Songbook (1996), Falling Forward (2007) and Broadway Stories (2011).
You can get a copy of Sandi Patty singing "I Can Only Imagine" by purchasing any number of Christian compilation CDs. This song is featured on many of them, and they are available at online retailers like Amazon.
The song "That's The Love of God" appeared on Sandi Patty's album "The Friendship Company: Open for Business", which was released in 1991. I don't know when it was recorded, but I hope this information is useful to you.