In that order shaper 3 gets you:
3d4 +3x con mod hp
6 skill points + 3xint mod + other modifiers for shaper skills
1 bonus feat (psionic, metapsionic, or psionic creation feat)
+1 BAB
+1 fort, +1 reflex, +3 will
11pp + bonus from being 3rd level in psion (int prime stat)
5 first level powers known
2 second level powers known
manifestor level 3 (note that you cant exceed this normally so even if you have 10 levels of warmind you astral construct power would still max out at 3rd manifestor level without special help)
vs
Psychic warrior 3
3d8 +3x con mod hp
6 skill points + 3xint mod + other modifiers for psychic warrior skills
2 bonus feats (psionic or fighter feat)
+2 BAB
+3 fort, +1 reflex, +1 will
3pp + bonus from being 3rd level psychic warrior (wis prime stat, same as warmind so less stat dependency, and with the initial stat penalty you may need the help)
3 1st level powers known (generally better at personal buffing)
manifestor level 3
Definately a hard choice in my mind ;/
You could get the construct faster by going through psion but if you wait until your first level of warmind to spend a feat and get it then you could use your warmind manifestor level to manifest it instead.. maybe your dm would allow you to convert 'practiced spellcaster' over into 'practiced manifestor' though.
Also, the DR gained by the warmind doesnt normally stack with the adamantine body feat (away from my books, I am assuming it grants 2/- DR) which makes the class a little less desireable overall.
I would definately suggest picking up a psicrystal however, if for nothing else the coolness factor. Levels in psion or psychic warrior will stack with warmind levels to determine its abilities.
If you want to go for interesting/cool/crazy and your dm is going to allow practiced manifestor then you could do something like this:
Fighter 2/Psychic warrior 2/psion 1/Warmind X
and get practiced manifestor for psychic warrior, psion, and warmind. You would have a ton of interesting options, but it would cost you.
Fighter 1/psychic warrior 4 could also work.
+4 BAB, 4 bonus feats, easy entry into warmind
Your will save will 'suck' though
Ahh well.. have fun with it!