Meh, another missed opportunity of Get To Work. An actual neighbourhood in (/on?) Sixam would have been great to make up for how small and uninteresting Magnolia Promenade is, but nope, it's basically just a hidden lot to collect alien plants and crystals.
I've made Oasis Springs my alien world. Bedrock Strait in particular (the neighbourhood where Johnny Zest lived before I threw him out to replace his trailer with a planetarium) is home to three alien families, a Sixam-themed nightclub and the aforementioned planetarium. If you want more of the Sixam feel, take a look at the gallery, some builders are really good at capturing its unique atmosphere. If you want a different alien world altogether... well, there can always be hope, but I'm afraid that ship has sailed. :(