well, as far as the weight of a 55 gallon, you should figure about 8 lbs per gallon--generally you have almost the same amount of gravel--so add another 55 lbs....then you have decorations, lid, filter, glass of tank, fish, etc....and i definately think you need a bigger tank if you want more than one oscar--if they are crowded, chances are one will kill the other eventually to give himself more room! and they grow really fast, so it wouldn 't be long before you would probably have trouble--my oscars have went from around 1 " to 8-9 inches in less than a year, and they are still growing a lot! everytime i look at them they look bigger...but they are super pets, lots of personality, and well worth the extra care they require--buy the bigger one if you can, or look in the paper for a used set up , most of the time they already have the filters, stand, deco, canopy, lights, etc. i bought a beautiful wooden stand and canopy, 55 gallon, came with filters, deco, and she tried to give me the gravel !! and i only paid 175 dollars for it all, and they even delivered the stand to my door! so if you want a bigger tank, just be patient and keep looking, you will soon find a great deal i am sure--lots of ppl buy the setups, then they kill all their fish accidentally because they don't know about the water chemistry, they try again, all the fish die--newbies tend to overcrowd the tank, and that is sure death if it's not watched very closely.....so they get frustrated and just want to get rid of it--that's exactly what happened to these ppl i bought from....so you get a setup that's hardly used for much less money...best of luck, let us know if you have any more questions....
). I am not sure if they are the right names, but if I get them I will find out. They are all breeding too, regardless of the conditions. The tanks are clean but not very interesting, just rocks and algae.
I wont tell if you wont. 
