In most cases, it is relatively simple to convert non-vtec ECUs to Vtec. The same PCB was used in several ECUs, with components added or left off as needed. Look for a part number like "02D011F0-1500" which was used in many 94-95 Civic ECUs. In many cases, you might need to look at One Wire To4 Wire O2 Sensor or Auto To Manual as well.
Conversion for 02 D01720-1500 boards
Conversion for 02 D011 F0-1500 boards
Conversion for 02 D01980-1500 boards
Conversion for P14 to P13 (Which board?)
Use 5050s as a VTEC driver for the above conversion