1991 honda prelude engine swap?

i have a 91 lude and i was wanting to do a engine swap in it....it has a 2.0si motor now(b20a5)and i was wanting to put a vtec motor in it...what motor will fit directy into my lude with the same and motor mounts? i was looking into the h22 vtec but i dont know what id need to change and how hard it would b