Don't have the chainsaw mill choose to go with a small bandmill IMO way better choice. At one time I would make lumber with my chainsaw, no fancy guides, it did the job. I did look into many different mills chainsaw and band mill. Ran a few different ones at shows band mill is what I felt was the best bang for the buck.
After a little more research it turns out a different chain is required also. I just don't think it's worth the effort given the mill down the road will cut for .45 Ft. As luck would have it, my welding buddy had a bad ass heavy duty trailer for sale so I bought it and I'll use that to haul my logs to the mill.Squerly. I have used one, years ago. The one we used was just a guide, every thing else was manual. It worked pretty good, but was a little more wasteful of wood than a bandsaw would have been. Not sure I would want to use one now, they were pretty labor intensive. Of course, there are some that have feeds and such to make them easier.
While you may have a chainsaw, you need a really big chainsaw if you want any speed or want to make a few guts a day without blowing it up. At least 90cc but 120cc is better.
You do not need another chain, but the ripping chain will leave a smother cut.