Do it yourself, it's not too hard if you have the right tools. I will actually be taking out my H22 shortly to swap in a new built block (so i can up the boost), me and a few friends will be doing it. It should take about a weekend and that is all. It is pretty much disconnecting lots of hoses and wires. Since you are going from a a h23 to a h22, you will need the right ecu and everything so make sure you have that. PM me if you have any questions.

If you really want a shop to do it, get DLB1994 to do it, he is on this forum and could get it done in much less than a month. Plan on spending at least $70/hr wherever you go.