Condo purchase buy and hold HELP financing deal

[Elon Revels]

I have a landlord who has agreed to sell me condo @51k. recent comps range from $63k to $79k. No work needed as of now. I have someone else prepared to rent for $800p/mo. I would like to acquire through LLC. as my first property. Doing a subject to ($43k owed on mort.) and take over payments. Putting $10k down towards the purchase price and later refinancing on a conventional 30yr. in 2-3 mos. after the property has seasoned. I am a newbie and I've never done any r.e. transactions. Any advice or proper steps to take?