I wonder if there is any real thorough book on this, I have the Scandinavian (2nd edition) by John Emms and it's still only 60 pages, and that include the Panov-Botvinnik attack.
2... Nf6-lines in the Scandinavian?

I've got a Plaskett book that does more justice to it. Though nobody does a good job of convincing me that the 3.Bb5+ lines can ever be pleasant to deal with.

I play that line in the Scandinavian although I have never read a book on it...I think the Scandinavian with 2)...Nf6 is simple enough that it can be played without much study although I don't think studying it would hurt.

Houska most likely covers it in her new book, but if she doesn't, then Emms' Scandinavian 2nd edition is probably enough to play it at most levels.

I know this doesn't answer your question but what the heck.
Analysis by Fire 1.31 w32:
1. +/= (0.45): 3.Nf3 Qxd5 4.Nc3 Qd6 5.d4 a6 6.Bd3 Nc6 7.0-0 Be6 8.Ne2 Bd5 9.Bf4 Qb4 10.Ne5 Nxe5 11.Bxe5 Qxb2 12.c4 Bc6 13.Bxc7 Rc8 14.Be5
2. +/= (0.40): 3.d4 Qxd5 4.Nc3 Qd6 5.Nf3 a6 6.Bd3 Nc6 7.0-0 Be6 8.Ne2 Bd5 9.Bf4 Qb4 10.Ne5 Nxe5 11.Bxe5 Qxb2 12.c4 Bc6 13.Bxc7 Rc8 14.Be5
3. +/= (0.28): 3.Nc3 Nxd5 4.Nf3 e6 5.d4 Bd6 6.Bc4 0-0 7.0-0 Nc6 8.Bd2 a6 9.Qe2 h6 10.Rfe1 Nf6 11.Ne4 b5 12.Bd3 Bb7
4. +/= (0.27): 3.Bb5+ Bd7 4.Bc4 c6 5.dxc6 Bxc6 6.Nf3 Qc7 7.d3 e6 8.Nc3 Bc5 9.0-0 0-0 10.a4 a6 11.Qe2 Nbd7 12.h3 h6 13.a5 Nh5 14.Be3 Nf4 15.Qd1
5. = (0.19): 3.Bc4 Nxd5 4.Nf3 Bf5 5.0-0 e6 6.d4 Nc6 7.Nc3 Ndb4 8.Bb3 Be7 9.a3 Nd5 10.Nxd5 exd5 11.c3 0-0 12.Bc2 Qd7 13.Bf4 Bd6 14.Bxd6 cxd6 15.Qd2 Rfe8 16.Rae1 h6
(, 23.07.2010)

Personally I like 1.e4 d5 2.exd5 Nf6 3.d4 Nxd5 4.c4 Nb6 5.Nf3 as white has a great position without any problems for black. Black will have some difficulty generating counterplay if white plays correctly.

Well, that line is quite to early to give a verdict on, black has many ideas to create counterplay, and he is hardly without play after just 5 moves in the mainline.
There are some lines though, mostly one that has convinced me that the Nf6 scandinavian is to unsound and I've given it up.
I just received Houska's book, "Starting Out: The Scandinavian." There are roughly 100 pages devoted to the Nf6 Lines. The rest of the book (about 200 pages) is devoted to the 3...Qa5 and 3...Qd6 lines.

Hi,
The best coverage I've found on that variation is given in Andrew Martin's DVD from the FOXY Openings Series:
Vol 100: The Modern Scandinavian & Icelandic Carnage
which is in fact an improved review (published in 2010) on his first (and somehow theoretically old-fashioned nowadays) DVD on the subject:
Vol 19: Center Counter Carnage!
Take care.
Which books has have the best coverage of the 2...Nf6-lines in the Scandinavian?