yeah, the loom will be nice and easy to do. they are nice and easy on those early to late 90's fire engines.
one thing to note though is the exhaust down pipe will need to be a little longer for any fire engine bigger than the 1.1
you can do this 3 ways..
the method i did where i just added 2cm worth of pipe to the down pipe by cutting it in half and welding new pipe in
adding a 2cm spacer between the down pipe and exhaust manifold, but you would have to remove the old studs and put longer ones in or use bolts.
or( as you wont have gear linkage rods) modding a punto down pipe. cutting it off and welding it on to the pandas original exhaust.
dont forget to swap the lambda sensors over too. the spi panda uses a 3 cable type sensor where as the 1.1 up uses a 4 cable type.
electronics wise, you would have the immobiliser to deal with. the best way to sort that out would be when buying the bigger engine, make sure you get the ECU, key and CODE box that lives near the steering wheel. you can find the code box by following the chip igntion barrel aerial wire back to a black box. when you get this, try to cut the wires back as far as you can.. make sure you get the plug.
connecting that up to the ECU is easy. the engines wiring harness will have one multi pin plug that connects the engine wiring harness with the rest of the car.
it looks scary but its easy.
for the CODE box, just match the wire colours.
the only other one you really need is the ignition live to the the ECU to turn on.. and that is an orange wire.
the alternator wiring would just be a strait swap over.
when its all in front of you its really easy.
dont forget to tart it all up too. good time to paint the engine block, check all the core plugs.. and a timing belt change is a dream to do when the engine is out of the car.
all things to think about doing before you stick the new engine in the car
check
here onwards for a bit of what is involved. forget any of the gearbox, gear linkage, or fuel problems i had as you would not get them. as far as electronics go, eventually i posted up a "how to" in the thread.