My last soldering iron needs to be retired, it will no longer melt solder, and was originally purchased sometime in the 80's. So I need a new soldering iron, but I do not know which one to buy. Should I get a 25 watt or 30 watt to make sure I have enough heat? Also are any of the soldering stations with the variable heat gun worth it? For now I will have to be careful and use my butane soldering iron (I have not burned any components yet).