re: Recommendations for attic insulation for older house in south Lousiana

I'm in a very similar situation and your house sounds exactly like mine. After recently researching those two options, I'm planning to go with blown in. It's cheaper and I can easily do it myself.

The spray foam provides more insulating properties, but is more expensive and generally not recommended for DIY. I was told by the installer when getting a quote on spray foam that I would need to seal off my attic ventilation from the outside and thus additional modifications to your HVAC would be required. I've also heard the spray foam can shorten the life of your roof.

Good luck!