If I had the cash and was finding that renting a week or month at a time was costing me a lot AND I had enough work, I'd buy a used machine/head and spend a little making the machine like new. I'd do my learning curve in a used machine and see what works for my situation. I was lucky when I started in that I had two machines. i made one a mulcher and owned several heads before settling on what works best for me and provides me the most uniform product. Now that I only own one machine capable of mulching, I have gotten to know all the ins and outs of this machine. I generally keep a machine I mulch with for 2-3 years. This one I may keep 3-5 years since it's been reliable.
It will come down to personal choice. I am weary of renting units and being stuck on someone else's schedule or being in a machine that's not set up the way I want it. If you are serious about the mulching, by all means rent and try one out, then get something that fits you. You will be more productive than the guys who rent and your quality will be a lot better as you become one with that machine. Too each his own as far as machine's go. I like Bobcat and a lot about CAT but I stick with Bobcat because I don't mulch full time (I also do excavation and a lot of grapple work moving trees/brush) so the Bobcat fits a wide range of services.
Nothing off the shelf is set up just right. Even with debris kits, guards, and this or that, you will need time with a machine to find all the places debris can enter your compartments. That's not good because of the heat mulchers can generate in warm weather. Sealing compartments is important and I've yet to see a stock machine that is sealed right even if it is "ready to mulch".
Just takes time owning/practicing to figure out what will work for your situation. Good luck.
