If you're looking for more xc oriented single track at south mountain, the defacto choice is Desert Classic, close to a 20 mi out and back if you choose to do it all. Of course though, there are tons of options ranging from that to DH oriented, which probably won't interest you from what you said. If you're looking for more techy but not DH only, definitely give National a shot.
If you're on the park sanctioned trails you won't need a guide, they are very well marked. Depending on when you go and which trail, they are highly used too so you'll never be too far from assistance if needed.
If you're on the park sanctioned trails you won't need a guide, they are very well marked. Depending on when you go and which trail, they are highly used too so you'll never be too far from assistance if needed.