Lending options to purchase property - hard money? Or??

[Rich McKee]

Looking for $50k asap to secure an investment property. 

I have found a property I would like to purchase (off market). This is for buy & hold, personal use, not primary residence. Property does not have a dwelling on it. It is a small farm. Purchase price is $450k. Sellers are asking for $50k immediately, an additional $200k within 90 days then willing to carry balance for 3 years with a balloon. The sellers need total of $250 within the 90 days for personal reasons. 

I have investment properties I am looking to sell. Separate properties including:

Mobile home park - value $350k

Single family home - value $200k

Vacant lant - value $250k

I own these properties free and clear. However there is not enough time for me to go through a standard loan process, accessing my equity. 

My question is what do you suggest I do to secure the property with $50k asap, as well as protect myself in the event my properties don't sell before the 90 days. 

Do I go to a hard money lender? Credit union potentially has line of credit option at around 10%. 

What other creative options would you suggest?