My boyfriend and I are beginning talks about him coming to visit from South Africa. If all goes as planned we hope to be engaged during that time, have him go back to sort out some things, and return to get married. The problem is the length of time everything takes to process. Is there a way to have someone be here while applying for either fiancé or spousal visas with out meaning that they are stuck away for months while everything is processed? Meaning is there an interim type visa that he could apply for to keep him here while we either wait to be married or if we do marry while I file for a spousal visa? Also can he work during this time?
Technical things: we are both of age and able to me married. We have known each other the required years. His first visit here will be less than 90 days so it requires no visa.
I do NOT want to get married with him here on a tourist visa. I know people do it, but I'm not willing to take that risk.
Thanks for any info.

Where is "here" what country are you in?

But you hire an immigration attorney in your country, since all the visa paper work is done though your nations immigration office. The main thing, will be that every form is done, and done correctly. And that every needed item is done

Im in the US. Forgot that detail. I'm not opposed to an attorney, just hoping to not have to have that expense if we could. But seems like it may be the best option