I would guess that a 15 watt iron would be hard to use on an MCPCB even for someone who does this all the time. Its easy for me to spend your money, but I would encourage you to look over at Texas_Aces power supply thread in which he talks about his bench set up, including a 60 Watt rework station.
Buy a good soldering station and cry once over the price rather than making do with sub par equipment and being miserable every time you use it - or worse - ruining expensive parts.