looking for a 4AGE 20v, plz help me

[NismoJin]

i have a chance to buy a 4AGE silvertop 20valve for my new AE-86 hatchi-roku. but the say it only needs ECU and harness. so im really looking for that but i was wondering if anyone knew where i could get a complete, ready to drop in, motor and tranny set. im not sure if its a good deal (the one im getting), im neverous that if i get it will will need more than the guy said. from osakajdmmotors.com. i have only owned nissans before so this is all new to me...please help me.