alfa 147 16v jtd = 150bhp and 220lb ft of torque as std
plenty of space under the bonnet to fit it in, just g'box WILL NOT TAKE IT, and the 147 box is bigger and set up for a wider front end.
I never knew there was an NA 1.9 till a few days back when I drove a mk2 NA D, it was the slowest stogiest thing I've ever driven (bar a grande punto 1.2 8v
) you've got teh weight of a diesel and no poke and from what the gauge seemed to be showing, no better fuel economy
AFAIK the 1.9d and jtd are similar so far as engine block and mounting, but the rest, no idea.
best bet would be to secure a whole 1.9jtd engine, ecu, engine side wiring loom and plug and play it.
its not like its THAT much more work than just fitting another engine of the same type, just need to change wiring over.
cost wise, the jtd won't cost you anymore than the NAd from a breakers (talking mayb £200-300 oooppp noorrff. and closer to £1k if south)