Aviation GPS for newbie

Thanks to advice from several people, I sold the Garmin Streetpilot that
was given to me as a gift and now wish to 'convert' it into an aviation
GPS.

I'm debating a Lowrance Airmap 1000 (or possibly a 500) and am curious
to hear opinions of happy/sad pilots who own it...

I have read as many online reviews as I can find and am curious to hear
from those on this list.

I feel as though it's prudent to get one with long-ish battery life (I
rent planes and find that cigarette lighters don't always work). Also
backup in case of power failure...

Yes, I'd like a Garmin 296 but don't have the extra grand...

Thanks,