not all GTP's come with HUD's i seen one with out it before it was pretty plain. cloth interior, no HUD, etc..
also top swap kits are pretty cheap, i had everything you needed for a top swap for sale for $350 besides the crank pulley.
but i do agree if your not handy with cars its easier to buy a GTP
plus having a 97 GT IIRC the trans is not an HD trans