yes. A turbo one would be a 4G63T

No, the 4g63T came in the GS-T and the GS-X only, I had a 1990(Talon TSi - same as GS-X), if you buy it, do the timing belt and head gasket before you get it home. The 1992 GS could have come with the 4g36 (1.8L SOHC) or the 4g63 (non-turbo).

im not sure about first gens but my 95 GS had a 420A (dodge neon motor)

I'm as sure on the first gen DSMs but on the second gen:
Eclipse GS and RS
-420A DOHC 2.0
Eclipse GST and GSX
-4G63T DOHC 2.0
Eclipse Spyder (GS, not the GST)
-4G64 SOHC 2.4

hope this helps

The Spyder GS-T came with a 2.0 4g63-t.
Anything with GS-T or GSX for the DSM years were 2.0 4g63-t powered.
Anything other for second gen was 420a.
For 1g non turbos there were the 1.8L 4g37 SOHC as well as a non-turbo 2.0 4g63A
The 2.4 4g64 were in gen 7 and 8 galants as far as I know.

Also, you can tell if it's the non-turbo 2.0 if it's 16v.  The 1.8L 4g37 were 8 valve

the mitsubishi 2000 motor is the 2.0 liter 4G63. But it did also have a crappy 1.8 liter SOHC motor. Also a word to anyone goin to buy one of these 1g or 2g eclipses. Don't buy one with an automatic transmission, you are just askin for troble. O and there was one more motor too for the eclipse the 4G64 but that didn't come out until the later years of the second gen. Personally i prefer a 4G63t motor. The first gen 4G63 compared to the 2nd gen 4G63 i believe is better. The first gen is a 6 bolt motor. The second gen a 7 bolt motor. The first gen motor i believe is more hardy and did not have issues with crankwalk, like some of the second gens had which is bad.