As White, I encountered the following move order last week:  1.e4 c5 2.Nc3 Nc6 3.g3 e6 4.Bg2 Nf6 5.d3 d5.

Later I consulted Lane's book and King's book on the Closed Sicilian, and I had a hard time locating this postion.  I started by looking under the "French Setups" which usually arise out of an earlier ...d5, e.g., 1.e4 c5 2.Nc3 e6 3.g3 d5.  And it doesn't yet fall into the 6.Be3 or 6.f4 types of main line positions either, although it could transpose.

So I'm wondering if maybe this is classified as something else?  I did find this position reversed arising from a lot of English openings (1.c4 e5 2.Nc3 Nc6 3.e3 g6 4.d4 d6 5.Nf3 Bg7) and even a transposition from a KID (1.d4 g6 2.Nf3 Bg7 3.c4 d6 4.Nc3 Nc6 5.e3 e5).

Also, it is common for White to exchange exd5 in the more pure forms of French setups, as in the game Spassky - Kasparov that can be found on this site.  But I'm thinking that may not be so good here, because Black has the option of capturing with the knight: 1.e4 c5 2.Nc3 Nc6 3.g3 e6 4.Bg2 Nf6 5.d3 d5 6.ed Nxd5 and I believe that this pawn structure is very favorable for Black, similar to a famous game Thomas - Alekhine, Idunnowhere, 1925. (I wonder if this pawn formation has a name, such as "Little Center With C-pawn instead of D-Pawn")

I did find a few games where White exhanged exd5, and a few more where he tried Nh3 with an eventual f4, and a few with Nge2, and a couple with an immediate f4.  Is 6.ed, in fact, dubious?  And what is the best plan for White here?