I've gotten both sidebars to show now - dumb coding error. And the app I found worked - the iPad sees the page the same way as the PC so that's good.
Just final decisions to make regarding adsense sizes and placement now that I've gotten both sidebars behaving. Vertical adlinks will work but not the horizontal ones. Leaderboards are out and I can live with that. Once I get this finalized and online I'm pretty sure my site will gain a good quantity of speed which is one of my main reasons for this change.
netmeg, many thanks for your help. I hope you can get yours working as you want it. I see this as a very worthwhile endeavour as it's no longer the web of the 90's and the use of smartphones and tablets is only going to increase.