Or, you can sell it to someone who is more equipped.Some may buy the deal from you, knock down the eight plex and build all new.

My main concern is the limited cash I have available for the down payment and renovation costs.

Or are you looking to raise money for the down payment? 

If you are cash flow positive, I would not pay it down. 

Spot development usually drags everything down around it.

The second  problem is it is difficult to find people who will do preparation of the land for the mobile hand ,and also  I don't really know what is better/easier/cheaper...putting concrete pillars in the ground every 8 feet or putting down an asphalt or concrete slab.

I have only done one eviction with a tenant that I inherited and he basically stalled out till the sheriff came to remove him so just be prepared for that if it goes down all the way to end. 

Well Don, it depends on the desirability of the asset to other possible buyers (As guessed at by me), as well as if the offer is predetermined to be a lowball offer.Some sellers do not have a lot of ability to go down much and a plethora of buyers may drive the price up above what I think it should sell for . 

I recently have been struggling with narrowing down a market that works for my strategy and wanted to get some insight from experienced investors. 

Seller is agreeing to do 90% seller finance at 9% interest, with a 10% down payment.