tbh, it wouldnt be massivly difficult to fabricate.
you'd just need an intake manifold made up, which wouldnt be anymore trouble than an exhaust manifold. you can pick up an eaton screwcharger on ebay for a decent sum.
it wouldnt be hard, just time consuming.
then youd need a proper ecu to get it all mapped nicely.
its something id like to have a look at doing one day. if done right twincharging is bloody brilliant.
look at the old micras!