OP hasn't been back since his original post on Christmas Day. Maybe he drank too much.
Touring frame with 26" wheels. I guess the wheels are on rim braked rims which rather limits your choices for "touring" bikes as most touring bikes were 700C unless you think specialist touring bikes with hand built frames which are ££££ or indeed off the shelf specialist touring bikes which also tend to be 700C. The only "touring" bike frame for 26" wheels that comes to mind is the Surly Long Haul Trucker but you ain't going to get one of these for peanuts or for free. In any case they have vertical rear drops not horizontal ones for IHG. You could still use your free wheels with Nexus IHG using either a chain tensioner which has already been suggested up thread which like some one else suggested a bit pointless if you intend using an IHG or you could not bother with an external chain tensioner but fit an eccentric bottom bracket as another way to tension the chain using this set up for a frame with vertical rear drop outs. Either way you are going to have to spend some money.
If the wheels were disc wheels you might stand a better chance of success as brakes would not be an issue as the braking is done by discs and not pads making contact with the wheel rims.
Also bear in mind if you do find a suitable frame, if it's a frame for 700C wheels and you fit 26" wheels then the bottom bracket may well be closer to the ground as the wheels are not so high meaning the pedals might strike the ground especially if you are turning sharply and leaning over as you pedal. 700c wheels on 26" frame bike can work but the other way you have to be careful.
The wheels with Nexus hub you got for free were probably free for a reason. Unless you can find a 26" frame with horizontal rear drop outs I would forget about using them as to build a bike around them could prove expensive and time consuming and just not worth it. Just get a complete touring bike off
Ebay.