All 26 episodes (both subbed and dubbed) are readily available to
stream on Funimation's website.
You can also buy the DVD set from
Funimation directly,
Amazon, or
Barnes & Noble.
I don't believe Puni Puni Poemy is available for sale or official streaming anymore at all, nor do I think anyone actually holds the license for it currently. While it's not my intention to illegally distribute copyrighted material, I would like to provide off-site streaming links so that people who missed the boat two decades ago can still watch it today:
Episode 1 (subbed)Episode 2 (subbed)Episode 1 (dubbed)Episode 2 (dubbed)I realize that the above links probably only apply to people in the US. Frankly, I'm not sure any company even currently holds the license for Excel Saga overseas. If you would like to add information on watching the anime or OVA in other territories (or in other languages), please reply to this post or PM me!