Your DB07 is like many of the Hondoids of old. It's a good solid bike with a good track record of being mechanically reliable. The exhaust on these can be different from bike to bike, like my X-Moto. It's basically the same thing as what you ordered.
Getting an exhaust to fit it without some modding or bending may be somewhat challenging. It's why I went with this.
https://www.amazon.com/FMF-Racing-20...spark+arrestor
Do all the normal stuff you've read here including the ever-important valve adjustment. They're guaranteed to be tight.
Here's the install thread.
http://chinariders.net/showthread.php?t=6954
I'd go with a pod filter just because the stock air box and the filter on that bike may not be all that good. The one in my X-Moto was junk. Our old kitchen sponge would have filtered better.
Odds are, this bike will arrive being geared to climb straight up a pine tree. The front sprocket is the same one that fits all Hondoids so you may find it easiest just to order a 17 tooth from CSC. The rear sprocket should be a a JTR269.XX unless they changed it for some reason, and can be purchased in many different teeth combinations.
Hope this helps!