300,
Since you didn't mention it, I'll conclude you are referring to the B18C motor. But any of the 1.8s (A, B, or C) would be a nice fit for the 914, especially since the car weighs less than 2400lbs. Kennedy Eng. Products list of 914 adapters appears to include Acura Integra 1990+, but I'd contact them with engine specifics to verify. This would be a good mate for the 914 transaxle since the torque is well below the 300ft/lb limit.
The first step is to get the dimensions of the engine front-rear (including drive & accessory belts back to the rear mounting face), dimensions top-bottom (including intake down to bottom oil pan). Also note any jogs in the oil pan profile since the stock engine bar runs side-to-side underneath it. Engine width shouldn't be an issue since the engine bay is very wide - more than enough for a V6, V8, or factory flat-8.
If you can get a sketch of the engine with the dimensions mentioned, I have a CAD model I can do a quick fit-check for you.
If you choose to go this route, avoid purchasing the 1.7L or 2.0L 914. Choose instead the least desirable 1.8L model - plus the cost will be less.
I'm currently doing a V6 transplant in my fourth 914 (1.8L). I bought a rough one so there's plenty of body work involved.
Take a look if interested.