You could include the stuff Doug recommends in his gear guide.
And there is a sales pitch straight from this web site, to people who respect his opinion, already written for you :-).
I'm sure they'd put a link on the web site for a donation.

Being a 'one-stop'shop will negate a lot of the shipping charge. There is spare postage to use when one buys light items.

A world of warning; starting a business with friends or relatives can be very dangerous if you don't treat them the same as any other employees. Some just won't work.
Simon