Re: Heater core or real rad?
1) If you've never worked with a torch/solder before it can be difficult and I would suggest going with something already setup. (Dtek Customs Procore is decent for teh $$$)
2) Sorry this i cannot answer, perhaps my bump will get more answers for you...
3) Fan shrouds aren't bad at all, for a cheap easy to make Tupperware Sandwich containers work well. Or you can use sheet metal or Pleaxi, but more work..
4) Don't think i would buy a 100 dollar Rad... Procore from Dtek is ready to go with a shroud for around 50, and works quite well.
5) Have you ever tried to make holes in a GI ammo can? thats some tough metal... I would use the tupperware if you want less work, wood, plexi, or a combination there of for a more custom external box.
Hope this helps...