Ok this is the deal i am getting a b16a head including everything, that has been already preped for ls vtec. I am getting this for like 800 bucks which is rather cheap. I got a apexi vtec controler, and now i want to know what other part do i need to upgrade or refresh in my b18a to make this ls/ vtec last atleast 30-40k miles with out no major problems? 
you still need to do alot of research you are going to get tore up on the boards with out researching first i found this out the hard way so i researched but you still need alot of stuff i will list it but this is the one time i will because i know how ya feel you have the head and the controller.
You need a:
Zydne one wire conversion (then you don’t need a knock sensor)
Vtec Oil Pump
Vtec Water Pump
Arp Rod Bolts or Shotpeened Piston Rods
if you don’t get a Zynde ECU then you need a knock sensor and have to get it tapped into one of the distributor holes then run a one of the 3 wires to the knock sensor the others have to go to the Vtec Solinoid and then somewhere else i don’t remember you also need the get a Vtec Distributor if it isn’t on the head already i think that is where the other wire might go i don’t reley know i have the one conversion. I think that should be able to last ya with out the rod bolts the current bolts will stretch and break and good buy engine. If you want to reinforce it more then get a z28 block girdle or a block saver or somthing. what i listed would be a pretty stonger enigine but i also descriped around $2000 also it matters how far your pocket goes.