Woo, hoo, Scotland!!!
Have you ever been to Jungle Kids in Dundee? (don't know if it is open anymore, think the owner was playing hoogerie pockerie with the 'lec'y meter), my DSs absolutely love it there, loads of fun, seems to cater well for a wide age group. However the food is awful.
The best food in a soft play IMO is in the new one in Dalgety Bay (Planet Play? Something like that.) They do a great range of finger foods (mostly organic, big platters of mini sausages, cheese cubes, potato wedges, carrot sticks, etc, etc, stuff my 6 year old was as happy with as my 3 year old), homebaked biscuits, various coffees, nice adult foods, organic fruit juice. My only complaints are however is that the soft play isn't very exciting, a bit bland, unlike Jungle Kids which seems to be a big adventure (in fact DS2 doesn't want to go back to Planet Play, or whatever it is called, as it is boring but would love to go back to Jungle Kids). Also the children are expected to eat within their playing time which IMO is crazy, personally think you should try and have a system that will let the children play for their 2 hours (or whatever), then get their shoes on and sit down and have a meal. That way you get your customer both ways, they pay for the play session, Mum (or whoever) usually has a coffee and cake/biscuit , then kids come out of soft play and everyone sits down and has lunch or dinner. If you are expected to eat during the play session I find this really off-putting and would probably not eat in the place (well appart from the obligatory coffee ) no matter how good the food.
One thing that stands out about both Jungle Kids and Planet Play is that there are staff in the play areas so parents can relax a little without wondering if wee Johnny is being thumped. The last time we were in Noah's Ark in Perth and Coco's (?) in Kirkcaldy one of the things that irked me was the lack of staff in the play areas.
Sorry for the biiiiig ramble and all the best with your project, although please do as NDP advises and pay a sub.
Whereabouts do you intend to open your play center?