Onja.....The prices aren't listed, but here are some tanks that should fit
Manchester Tank: RV Products . I know it would be cheaper to try and repair what you have, but as I said earlier, those fittings are almost impossible to remove after so many years. Heating them is not an option!!!!
We found that our tank was really overkill for the amount of propane we use each year. Manchester tank looked like they had several sizes that would fit in your compartment. You might even find one that can hang from the ceiling of the compartment and give you some extra storage.
Good Luck