I picked up a Mini Ductor Venom a few months ago for about $425 online. They make other models too.
Using this and prespraying with Kroil I've been able to unstick a substantial number of rust flaking bolts from the subframe of a '67 Firebird that's never been apart.
For me, it's much better heat control than the Oxy torch. But I suck at getting a torch tip at the right angle in tight spots.
http://www.theinductor.com/induction...odels/md-venom