Partnership : Adding a new partner in start up for marketing and Branding exclusively for one region

we are a start up who deals in providing IT Solutions to education sector, we are 6 months old and technical team is building up product and website and marketing is on in 2 regions already ans we pretty good in these 2 regions. We are looking to add one of our friend as a partner for marketing and branding purpose exclusively for third region, he is a potential guy and we believe that he can be assest to our start up but we are confused whether shall we go for 60-40 partnership to new member to whatever business new member is getting to us exclusively from region he is responsible for or shall we go for 20% partnership to this new member or is their any other way we can go for. Please suggest.