Mthein,
The first question I have is are you getting good income from the properties and are they all leased out to tenants..?? if not you need to look for ways to increase your existing rents or leases to procure or leverage a higher net income from your properties.
There are many avenues you can do creatively you just need to find the one that can work the best in your scenario.
To question # 1 Yes you can owner finance a buyer but make sure you are protected in the transaction to ensure you have some monetary committment if your buyer defaults. If you do owner finance make sure the bank does not find out or they could acclerate your loan especially if you are not making payments if you still are they usually do not call the loan for that.
2. You can sell the note to a note buyer but honestly the overlevaging will make it not very attractive to a note buyer but you need to create a seller financed note first then you would sell it to a note buyer.
Before you even setup the note you would want to be working with a note expert whom can assist you in properly structuring the note before you jump in from the my understanding most note investors can this " pre-flighting" the deal.
It sounds like you wish to create a wrap around but in most you would be pocketing the difference as your profit after you pay your note so that would not apply here.
If you can not move the property a longer hold may be the way until the market turns back around.
You need to think about what is my ultimate exit strategy on these properties and if you package the deal you potentially can sell it as a package to investors whom are very experienced in duplex and triplex type investments.
If I can help further feel free to contact me my info is in my signature file and I wish you the best of luck..
Thanks--Colin