I think half your idea is OK.
But don't nickel-dime the landlord. $292. Sheesh!!! Are you sure it's not $292.09?

I'd say to him, how about a $350 (nothing less than $300) deposit in US$. That way you implicitly acknowledge the inconvenience of him having to convert the dollars in the off chance he needed to, as well as the variability of the exchange rate.