The form is not the critical element, it is the comps and value development (which is true all the time anyway). I believe that site condos can be on a 1004 form, but if it were my report I'd tend to do it on a1073 form...just more clear as there is a line for HOA fees etc.
As far as if there is a discount for SFR homes vs the subject...(first of all, does subject own land or not, needs to be determined). This is a case where calling area RE agents can help. Survey and ask them. I have done a few of these years ago...and found that some buyers don't care and would buy either, other buyers do care and want a SFR for the simplicity of ownership and lack of regs. So imo, the prices might be similar but marketability different....the marketing time for subject might be 6 months, single family 2 months, for example.
Are there any listings in subject subdivision? Any expired or cancelled listings? If so, look at the agent names..if the same name crops up multiple times that agent may live in the complex or specialize in it and is worth a call.
Are there old sales in subject subdivision you can compare to sales of SFR back in time to see if there was a discount, can apply same % today, or if marketing times differed.
Imo, the best SFR comps would be those in communities with HOA fees/Puds, but that is not always possible either. Use the best comps and best info you can, will take additional research for sure.