Advice on dealing with Lender needed!

[James Allen]

Ok, so I have an offer in on an investment property right now. I'm having a dilemma because I got pre approved for a 15% conventional finance loan on an investment property going for $179,000. I have a total of $42,000 although the dilemma comes that $13,500 is in a Unsecured Personal Line of Credit. My lender is now telling me that I need to have that money in my bank account for more than 30 days so that it doesn't show on my bank statement as a big deposit. 

I was freaking out about this because I could lose the deal over that. I spoke with my real estate agent and she assured me that It would be fine because they just want to see that it's not cash coming from who knows where and that they can trace where it came from. She said that when they trace where it comes from, aka (the personal line of credit) it will be fine. So I've started talking to another lender who will hopefully be ok with this. (I should know by tomorrow) Although he also mentioned that he thought the minimum down payment for an investment property is 20% and that he was going to check that out. 

With that said, I wanted to know if I am to transfer my personal line of credit over to my bank account will they will view that as ok? Also, I'm confused why one lender says 15% is ok for investment property and the other says 20%? Which one is correct? 

Thanks so much in advance for your feedback!