GMail client alternatives (no Mail, Sparrow, or Outlook recommendations please)

Hi!

I'm looking for a suitable GMail client for my Mac. Here are my objections for the more popular ones:

* Mail - Takes up way too much space on my hard drive after it has downloaded all my email. I also wish that archiving emails was a direct feature. I've utilized a "hack" that lets me archive emails when I delete them, but sometimes I just want to delete them. I love the search capability and integration with Spotlight. Most of all I dislike how much space it is taking on my hard drive (which I know is needed for Spotlight). Would be open to suggestions to reduce the disk space usage.

* Sparrow - No interest in paying money for an app that is no longer supported by developers. Looks promising but I'm not pleased with all the complaints of the latest version hogging CPU and lowering battery life (primarily).

* Outlook 2011 - Well, I love Outlook 2011 and use it for my work's exchange email. I have always liked having separate apps for my personal and work emails. When I'm doing work, I don't like being bothered by personal emails and vice versa. On my phone I use the dedicated Exchange/OWA client Mail+ so that everything stays separate and notifications are easy to toggle back and forth between. Anyway, yeah, don't want to add personal email to Outlook. Rather use a different program.

Thanks for your suggestions.

OS X 10.8