In your previous thread, I think I told you one fish for a five gallon is plenty. Now you want to put two? Five gallons might seem okay for a couple fish, but the fish is going to live out the rest of his/her life in that tank. They need room to swim around and room to themselves. Also, your bio-load size would make it much harder to keep your water parameters safe for the inhabitants. I am possibly getting a 20 gallon tank for Christmas, and I plan on having three small fish in it. Three is the max I'll have in there. The normal rule of thumb is one inch of fish per five gallons. Keep in mind that not all small fish would be happy in a five gallon.
But, in the end, it's your tank and you can put whatever you want in it.
-lefty