Same thoughts on the other PSU... I just don't trust their PSU's I always recommend getting one built for a car environment. Now that Ive said that, they might have changed since I last used them so what I'm saying could be void but it is just my $0.02 after all.
EDIT: I was just looking at the new M4 PSU, right before you posted that link... It looks good, has anyone tried it out? How well dose it work?