Lead free solder is fine, if you know how to solder properly it isn't an issue.
If you're just doing a couple of small joints using thin wire to PCB a cheaper leccy iron will be fine. If you're likely to be doing more than that and soldering leads onto larger pieces such as the back of a pot then get an adjustable iron or a high wattage iron, for that, the hotter the betterer.
Any iron (small tip) can be used for SMD prototypes if you know what you're doing but for ease, you cant beat using the proper system.
I'm working on the assumption this is not for SMD and that you can just go borrow one?