Questions on nuts and bolts of Seller Financing

[Ben Staples]

Hello,

I'm working on my first seller financed deal and have a few pretty silly questions.  I've worked out the terms so that they are favorable to both myself and the seller, now I just have to actually execute on it to make things happy and am looking for anyone that has used seller financing to buy a long term buy and hold.  Here is what I've got for context, and then I'll follow up with my questions:

* Buyer with no mortgage, interested in holding the note

* We have agreed on a down payment that works for both of us, at an interest rate that works for the seller and still allows me to cashflow.  

* This would be a long term amortization between 20-30 years

* I don't yet have it under agreement, just looking to understand what to do next as we finalize things *Knock on wood*

My questions: 

* Are there specific real estate attorneys that focus on handling closings on seller financed deals?  If so how do I find them?

* Do I write up my own offer to purchase?  Any guidance on how to do this?

* For monitoring payments, in situations like this do people just write checks to the seller?  Or do people use some sort of escrow service to keep track of the payments and the loan amortization?

* I've read about people using balloon payments and refinancing into a conventional mortgage.  I am employed full time, so getting the financing would be no real issue.  I guess what I'm stuck on, is that right now I don't have the funds to put 25% down to go the conventional route, and have negotiated a lower down payment with the seller.  In 5 years, I would have been making payments to the seller, so it's not like I would be accruing the funds for that 25% down payment.  Am I missing something?  Is there any way to transfer this long term seller financed buy and hold into a conventional mortgage?  

Apologies for my ignorance.  If anyone has experience doing this and would be willing to hop on a call, please DM me!

Thanks

Ben