Is there a good alternative to SQL*PLUS for Oracle?
I presume that you want a low-overhead method of knocking out queries, but want more functions than SQL*Plus provides? Why not use Oracle's SQL Developer? It's free.
Install, make a new connection to your database, then just start typing a script. Press F5 to run it (or just the part of the script that you've highlighted).
Emacs can provide so much more powerful text editing features and functionality beyond the default SQL*Plus command-line interface.
Here are a few links on how to use Emacs as a wrapper for SQL*Plus: