Best replacement battery for H2?

[finall]

I can not find a good replacement battery for the 8-year old original OEM GM battery in our 2007 H2 SUV.

Anyone can recommend a good replacement, in the correct series/size?

I know that red-top Optima are smaller than the OEM battery. I love them, and used them in other vehicles and offroad too. But there is a fit issue.

The OEM battery is available from GM parts, and is REALLY expensive. But does an AGM (no free liquid) battery like the Optima exist for the H2?

What are people putting in as a replacement?

I want a high-end battery, so no bottom-of-the-barrel battery like Interstate or other junk. Willing to pay for something that will last and not splash acid around (the OEM never leaked).

Is the OEM still the best choice for replacement? I want to have this lined up before the OEM battery dies. I expect the 6-year rated OEM battery, which is now 8 years old, will go soon? What kind of life did you get from the OEM battery in your H2?

Thanks for the help!