The DSPs I looked at (the two in my first post) are sold in 196-pin MAP-BGA - is that surface mounted? I thought that was quite "socketable", but I don't know much.
Here are some specs/pics of the 196-pin MAP-BGA standard anyway...
http://e-www.motorola.com/files/dsp/doc/eng_bulletin/EB360.pdf
I think the other point you made is the most prohibitive though, isn't it? I thought it was easy to change voltages with a transformer, but apparently with chips it's not quite as straight forward? I don't understand, but I'll believe what I'm told :-) So yes, the 3.3v I/O could wreck things...