Now that I am in position, I would like to place a mobile home to generate some passive income, but I don't want to use my savings for the down payment.

@Tyler Speelman Your strategy to assist your sibling with a down payment while minimizing tax liability is creative but comes with complexities.

@Chris Ke With $200K for a down payment and the ability to invest full-time, consider starting with a 4-plex or multiple single-family homes (SFHs) within a 5-hour drive of Los Angeles in areas like San Bernardino or Riverside.

i shelled out big 20-25% down payments on my first few deals, and then realized... hey, this won't work for very long! 

This may sound harsh, but I would actually put this on the tenant to get his rent payment back.

I want to purchase an investment condo for $150,000.I want to get Heloc loan from my other investment condo for $50,000 and use it as downtown payment for this condo.Can I get a 30 year fixed conventional loan for $100,000 and use $50,000 for down payment from heloc?

This would need to be structured that if your rent is at or below your mortgage payment, the portion of the mortgage payment going towards principal is more than all other expenses (and hopefully more than budgeted capex). 

Assume you will be making payments in it.  

Is it foolish to consider using the HELOC for the down payment?

So, I am indeed getting monthly payment from my buyer that would cover both monthly mortgage payments and also provides me interest only payments on the difference between the sale price and mortgage payment.