Hi,
2nd part of your question is easy.
Moroso,
Stef's,
Billet Fab of Jeff Johnson's
Canton (I think)
All make a welded aluminum pan for your needs. There was a Moroso in the Racing Junk Classifieds a few weeks ago.
1st part of your question, I do not know. I will knock it around with some other guys who may know. I do thik that you may be on the right track though.
We have had several guys here swap from their dry sumps back to wet sumps and not lose any power but lose weight. One did it with a 5.750 stroke crank and still went as quick. We use the Titan Geroter Oil Pumps.
Ed