H22A swaps are very expensive. I wanted to do one but the prices to avoid little headaches, bigger brakes, custom down pipe (so I could have my car low), mounts them selves, labour costs, lossing the car for a week while the did the swap.
IF I had the cash to spend on this swap then I would do it. Here's one thing to think tho, you have to change the engine mounts completely, now if you blow the engine you can't simplely put a d-series back in while the H22 is being fixed (or replaced). With a b-series in a 5th gen tho, no mounts have to be changed so you can drop the d-series in while getting your b-series fixed. (this is assuming you only have one car).