what to do....

[ste00]

i am stuck on this one... was supposed to be getting a rx7 this weekend but the guy has pped me around again for the 2nd month...

so i have the s12 half sprayed sat in the drive.... most of a 200sx s13 (engine, loom, box ect)... and am drving a pug 406.... diesel

the s12 needs welding... drivers wing... rear seats and belts... and the engine sorting as it will idle but not rev (well it will rev but dies after u rev it when u try to get it to idle)...

i am trying to decide what to do should i:

Look for another 200sx s14 and keep the s12 to do up over time?
Throw more money at the s12 and get it done quick as poss?
Throw more money as the s12 and fit the engine out of the s13 in it (not sure how to do this or what is needed) and get it done asap?