An all-Ireland team is actually pretty strong, with the centre forward position being the only serious weak link. As a starting point in terms of obvious balance (and prioritising some personal favourites namely Duff) I'd go with something like this:
Jennings is by far the standout keeper, and with due respect to the likes of Lawrenson, Moran and especially Tony Dunne I'd keep the back four as it is too. Danny Blanchflower really should be in there, so I'd probably shunt Brady out to a David Silva-esque wide playmaker role, move Best to the left wing and drop Duff.
Up front, Stapleton seems a bit underwhelming but the only orthodox alternatives I can think of off hand are David Healy and Robbie Keane, both great for their national teams but underwhelming in an all-time context, particularly Healy. So for an experimental line up I'm tempted to stick the skilful but highly robust Whiteside up front for something like this:
There's a nice balance between north and south in that second line up, with 7 RoI players and 4 from Northern Ireland, which broadly reflects the relative populations of the two areas.
There's excellent quality in reserve in the midfield area, with the likes of Ray Houghton, Ronnie Whelan and Sammy McIlroy deserving a mention. There's plenty in reserve in the creative wide areas too: Steve Heighway (37th in the latest Scouse list of '100 Players Who Shook The Kop'), the wonderfully talented Billy Whelnan who died in the Munich Disaster, and going much further back the highly-regarded Celtic star
Patsy Gallacher.
I've been typing this whilst cooking dinner so I'm probably missing someone blatantly obvious, but the only one that springs to mind is John Aldridge, who does deserve a mention but he can feck off as he's a knob.