most land finacing by local banks do require 30% down payment. And the area that this lot is in may have building restrictions.
land is always a long term investment by developers or owners. In most cases they are not in a hurry to sell.
Good Luck and you do NEED a buyers agent to best represnt your interests
You should get a loan for the land first separate from the construction loan. Construction loans often use the land equity towards the down payment requirements, and are often
The development may have some requirements for building your new home. Some require a minimum square footage, or price point. You will want to talk to a lender about a construction loan where you can wrap the lot and construction together.