I think there's a page on Ladbrokes which offer up odds for finals and it should allow you to post a double bet. You're currently 12-1 for the NRC and probably something similar with the GF. A £10 double should net you a lovely £1,440.
I think any bookie on this planet would be willing to take your money off you for that one - and give very generous odds! Mind you, I would be the first one to congratulate you if you won it!
Luck is a combination of preparation and opportunity
Just to avoid confusion Starbug is the username of Steven Pike
SOMEBODY SAID that it couldn’t be done But he with a chuckle replied That “maybe it couldn’t,” but he would be one Who wouldn’t say so till he’d tried. So he buckled right in with the trace of a grin On his face. If he worried he hid it. He started to sing as he tackled the thing That couldn’t be done, and he did it!