put it this way, if i was you, i would buy the jebo
I have bought about 4 jebo heaters (i think) of those people and they are all sweet.
The only time i would fork out big $$ for a heater like the jager is when you have a tank full of expensive (as is 100's of dollars) fish.
The goldfish hanging on the bottom i dont know alot about as i dont keep goldfish myself but if it was a tetra of some sort then i would keep an eye on it and make sure it doesnt get any worse.
It may be a case of it being bullied, infection other that WS as you mentioned, or it may just be acting funny and will be right tomorrow. I wouldnt worry about it untill it got worse...
Good idea to get test kits, i got my master test kit off trademe for $45 and $5 postage, it has ammonia, nitrite, nitrate and Ph
HTH
Rogan