Hi mrgreen and thanks to the suggestion.
I guess what I would like to know is, if there are some brokers, who'd allow me to choose the resultant leverage by clicking and choosing the leverage I'd desire. If the leverage I need is 5:1, I would simply opt for the 5:1 alternative.
But if this isn't how it works and everyone should compute its leverage and the amount of lots manually, than OK, I don't mind it.
I apologize beforehand, if my questions are too n00bish, but this is something I really don't know (yet).