Hi
I know you need start up funding and your best bet is to borrow capital or to partner with someone. While there are advantages is getting yourself out there real fast, there are still some pros and cons. I would suggest the following:
a) Sit down and do a business plan or a projection for the next 5 years
b) Look at the capital that you would need to get you off the ground and to get you al least through the teething stages (say the first year)
c) When you have done that, look around you to see what do you have to put into the business, Eg: will you sell your car, how about the nest egg you had saved? what pieces of furniture can you sell?
d) When that is completed, check to see how near are you to the capital you need.
At that point if you still need a partner, carefully think why and who would you partner with. Remember the greater amount the partner puts it, the more they are going to require from you and the business. Think on what amount of shares are you willing to give up to someone. Who will do the marketing etc?
Remember your dream is yours, your partner must be able to see it through the same lenses.
There is so much to know, but carefully weigh all your options
Hope you find this helpful, feel free to ask me any further questions

You need to have a lawyer draw up non-disclosure and/or non-compete documents. Then have your lenders/investors sign them. However, that will alienate some lenders. Risk of someone taking your opportunities is a risk of doing business. It sucks to stick your neck out and risk getting taken advantage of, but sometimes that is the cost of doing business. However, just because a competitor tries to perform the same arbitrage does not mean they will be successful. Finally, the moment you start making money from an arbitrage, the the market will become aware and others will discover it on their own (that is the efficiency of the market).