Gorden,
After 13 years of doing "Subject-to" deals and the level of detail required for this type of deal I would caution you on doing what you are asking. I'm not saying DON'T do them however it's my opinion that if you sell/assign to an in-experienced investor that doesn't know what he is doing or doesn't live up to his end of the agreement and maintain the payments you could be opening yourself up to a huge headache. I take the "Subject-to" type transaction very serious with regards to protecting the sellers credit and doing everything in my power to ensure the payments are made and the investor you assign to may not, therefor opening yourself up to a problem. "Subject-to" deals also have alot of moving parts/details to them to make them work smoothly and if the investor doesn't know how to handle them there could be alot of issues for both the buyer and seller. With the correct highly educated and experienced investor, proper explanation, disclosure, and documentation you may be ok but be careful.