Fantastic news! Thanks tracke. 

Ive allready commented on both books with regard to the marshall coverage.
Both are quite good books in their own way.

Coverage

a) Attacking the Spanish covers the Gajewski and the Schliemann
b) Fighting the Spanish covers white's 4th, 5th and 6th move alternatives
c) The coverage of the anti-Marshall in fighting the Spanish is more comprehensive in Fighting the Spanish
d) The coverage of the Marshall variations starting with 12.d3 is more
detailed in Attacking the Spanish.

Style

Brunello's book relies more on presenting exhaustive variations, than verbal explanations. In the Marshall several of his variations run up till move 35, which is a bit much even for my taste. Most of these variations are void of any explanation, which will make them a bit bewildering for lower rated players.

Pavlovic book contains good verbal explanations, but provides only key variations, to the point that some side variations have been excluded that I think should have presented.
His clear way of explaining work especially well in the chapters on the anti-Marshall which I think are excellent.

novelties and error's
Both books contain several novelties. Though I found that
about half the novelties claimed by Brunello in the Marshall chapters, had been published or played before, and only testify to the fact that he should have checked more sources.

Error's are inevitable in openings books. In Pavlovic book I did identify some analytical error's, while these type of error's are rare in Brunello's book.
On the other hand, I did found some error's of judgement in Brunello's. These include long variations where a simple positional solution exists, and some curious misjudgements of endgames.

Recommendations

If you are not taking up the Marshall defence but the Schliemann, of course Brunello's book is for choice.

If you are going to include the Marshall for the first time in your repertoire, or you are playing the Marshall only OTB (and not in correspondence play) I recommend Pavlovic book, because you will much easier acquire the skills to play in the spirit of the Marshall  after studying Pavlovic explanations.
Also for lower rated players, Pavlovic book is more suitable than Brunello's I think.

If you are allready an experienced Marshall player Brunello's book will perhaps be more useful than Pavlovic, although even experienced Marshall players can learn a thing or two on handling the anti-Marshall from his book.

[color=#ff0000]Finally I can recommend both book's. [/color]

Fighting the Ruy Lopez, for the following reasons:

a) It is by GM Milos Pavlovic with the touch of Jovanka Houska!
b) You found ideas and one book for one defence.
c) Both books are excellent and 5 ***** by the critic.

Having said that, Attacking the Ruy Lopez is also quite a good book.   
 

I'm looking at new books and I'm wondering if I should get either Attacking the Spanish or Fighting the Ruy Lopez.  Do I need both?  Do these two books have a lot of overlap in the suggested repertoires or do they complement each other?