I can't speak for the LMM, but on my LB7, my $$ would go for EFI w/a DSP5. :thumb:
I went the Banks route the first time (they make a nice system), it was OK (I am sure other "modules" are similar), but you get more flexibility with EFI...and when you have to make a change, you can tune your truck to match your components (in my case it was a new mod CP3...thanks Pat!).
If you do get bit by the HP bug, EFI is a MUCH better place to start, it will save you big bucks. There are a number of vendors on this site that can set you up with a good set of tunes.
FWIW, I get much better mileage now than when I started...as long as I can keep from lighting off the HTT!