I grew up singing "Plenty Good Room" this way:

Plenty good room, plenty good room,
Plenty good room in my Father's kingdom
Plenty good room, plenty good room,
Choose your seat
and sit down.

**

I found a couple of versions of this song on YouTube that give the words as "Plenty good room on the glory train".

Here's one example:
http://www.youtube.com/watch?v=reid94PinJk

Added March 08, 2007 ; From NathanD2006
"Plenty Good Room from the "Music in Our Schools" month concert at Countryside High School - March 8th, 2007".