This line has the added benefit that Black can play it regardless of his mainline Sicilien (in case of 2.c3), e.g. 1.e4 c5 2.c3 Nf6 3.e5 Nd5 4.d4 cd 5.cd and only now 5...e6.

If OP asks from Black's point of view, he can find some comfort in Taimanov books. For instance, Semkov in The Taimanov Scheveningen Hybrid presents an interesting system with 1.e4 c5 .Nf3 e6 3.c3 Nf5 4.e5 Nd5 5.d4 cd 6.cd b6 (instead of ...d6 mainlines which are not that appealing for Black anyway): 

NB. After 1.e4 c5 2.Nf3 e6 3.c3 Nf6 4.e5 Nd5 5.Bc4, Semkov prefers 5...Nb6 6.Bb3 d6 with a lively position.

For White, an additional reference is Khalifman+Soloviev (KS) Squeezing the Sicilian, which focuses on the Alapin.
There is a great review of KS by IM Dirk Shuh on the Niggemann site, saying for instance about their 1.e4 c5 2.c3 Nf6 3.e5 Nd5 4.Nf3 e6 5.Bc4 line:
The authors use a hybrid variation by first playing 4.Nf3 and after the one main complex 4. ...Nc6 then allowing 5.d4 to follow, but after 4. ...e6 only interspersing 5.Bc4. They cleverly avoid the line 1.e4 c5 2.c3 Nf6 3.e5 Nd5 4.Nf3 e6 5.d4 cxd4 6.cxd4 b6, which I don't really like from White's point of view either. If Black now plays after 5.Bc4 b6, 6.d4 still follows and after Bb7 7.0-0 cxd4 Nxd4 can now come, after which White will sooner or later have good attacking opportunities on the kingside with Qg4 or Qh5.

I guess my title says it all.  I'm looking for good study material in the line 2.Nf3 e6 3.c3 (3...d5 4.e5).  Interestingly I play 2.c3 against the Sicilian but plan on a transposition from the French if allowed: 1.e4 e6 2.c3 d5 3.e5 c5 4.e5

Thanks in advance for any suggestions!