20 Gallon Paludarium for some kind of lizard?

[dinodeep]

Hi I am a student who is making a paludarium (half water and half land) for a school project. The problem with this is I really want a lizard that meets the following requirements:

-Does not require UVB
-Has ability to swim (water is 8 inches deep)
-Won't eat fish like guppies
-Can live in 20 gallons (essentially 10 with the water portion)
-Price does not exceed 30 dollars (I live in Canada by the way)
-Not a crested gecko (My classroom already has one)

I was thinking of getting a leopard gecko. Basically, I don't really know what lizard to go with. Any suggestions?

Thanks in advance!