Buying each property into multiple LLC vs Creating a Series LLC

I have 2 rental properties that I own on my name in Houston Tx since last 3 years. Property value is property 1 = $ 75 K and property 2 = 350K. I also own a single member LLC in Texas that I formed few years back for real estate investment but never got a chance to moved the properties to this LLC. My questions is whether,

I should move both the LLCs into this LLC as-is

OR 

should I convert this LLC into a series LLC and then create 2 entity under that for each property and move there

OR

Should I create one more LLC and move each property to completely separate LLCs

 Regards