I’ve always resorted to camping trips, to me, organised events never feel very epic (I stress the ‘to me’ bit there, I’m not disputing the epicness of certain events! 😀 )
Wether or not camping trips are affordable depends on how much kit you already have though. Expense aside, you can spend many happy weeks poring over maps planning your route, making it as ‘epic’ as you please by incorporating as many or as few big hills, famous landmarks, bothies and empty glens as you please. The more remote it is, the more epic it will feel.
I’d suggest starting with a route that you know is rideable however, although hike-a-bike can still be ‘epic’, its not a great deal of fun day after day…
My next epic on the bike will probably be the coast of scotland. You could make this a camping trip with a lightly loaded tourer (no need to carry masses of food) or make it lighter still but fork out for hostels every night. I’m still undecided…