Sorry, no cichlids small enough to fit in anything less than a 15g, and you can't really take all the puffers and shrimp back. Also, I wouldn't trust Petsmart for plants, the ones I've seen were horrendous.
This is an interesting thread, so many possibilities. Can't wait to see what you settle on.
My local Petsmart actually has an okay selection of plants. I do think a couple are not true aquatic (some grass looking things and bamboo) but they do have java fern, hornwort, wisteria, crypts, and some others I didn't buy because they need higher light. This last week their java fern was actually lace java fern! Too bad I just ordered some from elsewhere last month. These plants are not the ones in the plastic tubes but are in a separate plants tank.
i just thought of somthing...... how am i gunna swap substraits?
can i put all the shrimp in one bucket and the puffers in another how long will it take for this really fine sand to settle enough so that i can put the puffs back in?
what I did when I used TMS in my 30. I placed a piece of plywood on the sand in the bottom of the tank and started pouring the water directly onto the wood so it disrupts the sand less. As the filling progresses the wood will float and you keep pouring onto the wood.
when I did this, my 30 had settled completely within the hour.
side note: This may be an incredibly bad thing to do for one reason or another but in my case I couldn't have both tanks set up simultaneously for any lenght of time. I also kickstarted the cycle with all of the substrate rom my previous tank along with all of the water from it and the old filter as well.
looks like some pretty good rock. make sure there is not any copper veins running through them. also, put them in the tank with caution, just in case they still have the residue of insecticides on them.