I would like to ask if it is possible that the number 144,000 is a symbolic number fullness? It seems to me that in Revelation 7:4 is the symbolic figure of all Israel, and in Revelation 14:3 is a symbolic number fullness of the Gentiles.
In the case of the 144,000 in Rev. 7 I take it to be a literal number for the following reasons. First, the number is broken down into 12 portions of 12,000 each. And second it can’t be symbolic of all of Israel because 2 tribes, Dan and Ephraim, are not mentioned. And yet these two tribes will be represented in the re-division of the land following the 2nd Coming. Dan (Ezekiel 48:1) and Ephraim (Ezekiel 48:5) will both receive tribal allotments.
But like you, I believe the 144, 000 mentioned in Rev. 14:4 is symbolic of the raptured Church. They have been redeemed from Earth, are pure, have been purchased from among men (implying Jew and Gentile), and follow the Lamb where ever He goes. These are qualities unique to the church.
Here’s a link to a study I wrote on this subject that contains more detail on the differences between these two groups.