I have started a small business based around a machine which can fabricate parts from a limited subset of material. I eventually want to get a larger machine which will remove the limitations but I simply don't have the cash (or credit) at this moment. So, I want to 'partner' with another local supplier in the meantime so that I can take orders for any materials from the start. For now, I will simply funnel the larger work to this supplier until I eventually have the funds to purchase my own machine.
My question is do I need any type of legal agreement with this supplier? There are requirements I'd have (quote turnaround time, maximum lead time, etc) and I am sure there are requirements he'd have. Where do I start?
Yes, you and the supplier should have a written agreement.
Your requirements are sufficiently specific that you probably will not be able to find someone else's existing agreement that will do the job. However, any experienced business lawyer should be able to help you put together an agreement fairly easily (so long as you and the supplier agree on business terms).
You are looking for a Service Level Agreement. You must have an agreement in any case which supports your requirements. I recommend you to have an agreement with the supplier, spesifically supporting your own requirements, but I am not sure you have the power of bargain for that contract! So get it if you can, but it is probably unlikely.