I echo the other comments. Most mobile home parks have a few agents that specialize in them. Additionally, if you do drive through parks as someone suggested, you will find a lot of For Sale By Owners (FSBO's). Keep in mind, just because you find a FSBO, you can still use an agent to represent you and make your interest is protected. By doing so the Seller may pay the Realtor fees, but in some cases you may have to pay your Agent, but either way you'll have representation.
I don't think it's too early to start looking.
I disagree that the inventory will change much between now and June. I have seen mobile homes sit on the market for months.