The One Ring
http://wiki.maemo.org/The_One_Ring

DialCentral
http://wiki.maemo.org/DialCentral

Starting out so late on this will probably give you a terrible headache.

Try your best and if you get stuck at some place, someone here can probably help you. Be as specific as you can though.

Two other things to consider is using Modest, the built in Email app or Claws mail, both using POP along with IMAP.

Just have all of your Google Voice text messages forwarded to your Gmail account.

This way you can also get a ring tone as well when receiving something new.

That's how I have my setup currently.

For responding back, I use Tear, with 0.8 zoom_step and go to
google.com/voice/m
and zoom in once which give a 180% zoomed in screen.

Good luck.