Stock My 20 Gallon/ideas For My 20 Gallon!

[cooledwhip]

hey everyone. A friend of mine had a 20 gallon tank with a pretty old tetra HOB filter, a old, (AND RECALLED XD) topfin HT150 heater, as well as 5 Pipidae frogs that he raised from tadpoles from those infomercials on TV. pretty funny actually, considering the largest is about a foot long... Anyway. I got them out of the 20 gallon, and I went to the home improvement store and bought a 30 gallon tub. I put them in the tub, figured it was cheaper than spending money on a tank as it will just be cloudy anyway as these guys are legit HOGS. 
 
Anyway, I wanted to know what I should put in the 20 gallon. I actually have a "species list" of species I eventually want to keep sometime. Here are the ones I was considering: German Blue Ram/gold ram, cory cat, cherry barb, dwarf rasboras. I really only want to keep a single species in this tank, as well as some simple to grow plants like swords, etc.
 
I don't know if the heater is a collectors item or anything lol. If I called them or something would they send me a replacement heater? Thanks

I'm free for lots of other suggestions for stocking this tank btw.

 

[NickAu]

To save anybody else having to ask or look, Can you please tell us about your water parameters?

 

[cooledwhip]

It's not even filled up with water yet. I don't have any hardware or anything, just the tank. Ammonia will be around 0, nitrate/nitrite at 0. I live in a suburb of chicago. Here is my exact town water report last year: http/www.libertyville.com/DocumentCenter/View/14652
 
I know it doesn't say pH but I think it would be safe to say that it is 7-8 pH. I know thats a fairly large gap, sorry. I wanted to do GBR's and some rummynose tetras