Re: Mackie DL806, what do I need to make it work?
Lisa, with wireless access points it's all about the RF first (just like radio mics), and then access management for the illusion of security. We've had several discussions about both and I think using the site's search tool or the G-word search for "whats the best router for my mixer" "best for.... iPad", etc will give you hours of confused reading enjoyment (ok, not really enjoyable).
What's your budget? Without getting into enterprise-level gear, there is a lot of positive comment about Ubiquity Networks Nano and Bullet series, and Engenius ENS500EXT. Based on my experience with that Engenius product I am also using their ESR900 (now discontinued). I've been very happy.
Like Timo said, get the antenna (probably the whole device unless you get something like the Bullet) well above head height and you will have better results. I use a mic stand and boom.
As for which iPad or Android tablet... I have an iPad 2 but I don't have a DL806, so I have no idea if it's sufficient. It still runs the mixer apps I use: X32/M32, ViSi, MixTender, StageMixand the Audio Architect/Crown amp apps. Android - I have an ASUS Google Nexus 7 Gen2 and it's a great tablet. The other ASUS tablets are nice, as are the Samsungs. Again, no Mackie so I can't say how well any individual device might work in your application.
Have fun, good luck.
Tim Mc