The Creative Investor - Selling my own home on Land Contract

We are somewhat new investors in the Chicago suburban area with one rental soon to be L/O house and the fixer upper that we live in. We have been in the fixer upper for a couple of years and most of the work is done. I want to sell this prop. on a land contract - it should appraise for around $150. maybe slightly less.

I have read that you should get at least 10% down on owner finance deals, is this realistic to expect someone to come up with 15k cash down payment? Should I expect to have a long waiting period before the house sells with this kind of cash down payment or is this high demand terms that typically move fast?

We will refinance before sale on an 2 yr. ARM and pull enough cash out to buy our next house. I have a great mortgage broker that commonly refinances these credit challenged buyers out of land contracts. The rate will be 5% on my new loan - how many points higher than the underlying financing is owner financing usually set at?
Thanks in Advance!

Selling my own home on Land Contract - How much $ down?