i have had this conversion done all though it wasn't just na to turbo it was also auto to manual too.
like everyone has said what you will need is:-
sr20det engine and gearbox (if you have a manual box already then that will work)
i needed a new ecu because i went manual aswell but not sure about yours don't think you need it.
some rewiring will have to be done though obviously (don;t know what this would be)
you will need a different exhaust or a downpipe
like trial said you will defo need to upgrade the brakes and wheels (if they are stock) as they won't fit over your new brakes.
also if your changing the brakes/disks imo it would be a hell of a lot cheaper to buy a s14 or a s14a for like £800 - £2000 and take the engine out, swap the rear subframes and same with the front and break the remainder of the car and recoup some money
that is the cheapest option.
if you do do this though you might find you will need to use some of the s15 hub and the s14 hub because of the abs on the s15, for some reason my s14 calipers wouldn't fit straight on. Also the speed sensor for the s15 is on the diff on the s15 not on the gearbox so make sure you sort this if using the rear subframe fromt he s14
hope this helps mate
havent mentioned the obvious because i already have a 2way cusco diff, apex coilovers
