Recommended Soldering Iron

My son wants to build his first headphone amp (kit). He's asking for a soldering iron for Christmas. Can anyone offer up some information on what I should be looking for? He wants to start off with one of those Altoid can amps and work up to tube. I don't want to go too cheap but rather a decent one he can sell if he loses interest. He's 19 so we don't need the Easy Bake Iron. Any information is greatly appreciated.
Hi everyone. I ended up getting my son the Hakko soldering station. He's about ready to order his first head amp kit to try his hand at this. He's been reading and watching various educational videos. I was wondering what solder works the best. I was talking to guys at work, one of who is a robotics grad. He said to use solder with lead. Any opinions on this and is there a go to brand? Thanks for any info you can provide. Also I'd like to thank you all for the iron recommendations. You should have seen his face when he opened his gift.
Lead makes for terrible sound. Buy either Wonder Signature Solder or WBT Silver Solder. Silver bearing solder DOES make and audible improvement. Both are a pleasure with which to work. ( ) ( )
"Lead makes for terrible sound"

Quite an overstatement considering silver solders are only about 2-4% Ag, with the rest being the traditional lead/tin mix (though some are available in lead-free versions). I personally loathe lead-free solder, as it doesn't have the same wetting or flow properties of normal, lead-based solder, and (to my ears) sounds considerably worse. I also tend to think that as an adult, the supposed dangers of lead solder are quite overblown. Don't eat it or suck in huge amounts of fumes and you'll be fine.
Lead and tin have 7% and 15%(respectively) the conductivity of copper(the standard or 100%, on the IACS conductivity scale). Only silver(105%) has a higher conductivity rating than copper. It doesn't take much silver, added to a lead-based solder, to make an audible improvement. That some can't, don't or won't appreciate that; doesn't surprise me a bit(to each his own). Further- the solders I mentioned flow at lower temps, making the job faster/easier(a pleasure), and lowering the risk of damaging the component being soldered. Their fluxes are also easier on some of the metals found in our audio gear, than those in standard 60/40 solders.
I like using Cardas lead silver solder with a little copper. A joy to work with . Lead free solder is useless. Too narrow a temperature flow range. Resolder a lead free joint and you get moonscape. The fumes are not lead but flux, and you should not breath lead free solder fumes either. Lead free joints crack easier and behave like a cold solder joint. On a tube socket, lead free can be a disaster. If it works great for you I tip my hat. In my hands, I only make leaded work. Sonically lead free was too bright as well. Jallen