Bedchair , i would look secondhand , its a minefield .....narrow / wide ...with wihtout mattress... then theirs the weight .
I would suggest having a look in a local Tackle shop to get some ideas ,the same with Bivvys
I have the Nash indulgence bedchair, realy heavy but with lovely thick mattress which can be removed , i love it.
I also have the Fox Supa brolly system , brilliant ...... Nash Titan TT Viper with winter and extreme wraps once again brilliant.