Do like I am drive it the way it is and buy everything and do it at once. I have an 87 SD car. I put a K&N filter not a CAI, because when I go MAF I will need a different one. I put headers and full exhaust. I bumped my timing to 14* and added 373 gears. The rest I did was cosmetic. If you do it like you say you will be doing some things twice. You can do the few things I did and still use them later after the MAF conversion.
I've already got my new ECU and harness, Cobra upper & lower, 255lph fuel pump. 70MM TB and DSS 331 rotating assembly. I still need heads, cam, injectors, MAF sensor, CAI and the rest of the little crap to make it right. When I have everything I will pull the motor and do it up.