1990 GS Teg Engine Problem

Ok, my buddy has a 1990 Integra GS wit a b18a1 naturally. Now some shit went wrong in his cylinder head so he is aquiring a newer b18b1 engine. Now this car is for his wife, so please no replies on performance and horsepower figures,basically he wants me to find out what is nesassary to swap in the whole new engine (mounts,wiring harness,sensors, etc etc) and how difficult that would be vers cost effective. OR,even better he would like to know if the b18b1 head can be swapped onto his b18a1 block to save time,money,and headaches. And how difficult would the head swap be?if at all possible.
for now i think that is all he wants to know.
Recap- B18A1 to B18B1 :difficulty and cost?
B18B1 Head onto a B18A1 block : Possible? Difficulty and cost?

Thanks Guys