Why give up equity?

Will these people be offering genuine marketing (tailoring and designing your product to address specifically identified markets) or will they just be 'sales guys'?

If these folks will just be bringing in contacts and shilling the work you create, I'd recommend offering them a very lucrative commission on sales instead. Say, a ridiculously high percentage for the first n-years, with that amount declining over time to a regular commission as scale and sales revenue increases. Then, these people will only be rewarded (and rewarded handsomely) if they deliver on what they say they can produce while you retain full ownership of the intellectual property you will have 100% role and responsibility in creating.