9V 1amp bricks, which I think is what they are telling you, are widely available, Farnell, sure, but you can probably get one at Maplins also, or probably Dixons/Comet.
This reminds me of when my brother in law's father expressed a desire to wake up with a nice cup of tea in tennessee, so my parents sent him a Goblin teasmade, unfortunately, at 60 not 50 cycles, it woke him up in the early hours! In the 60's only Harrods could provide a bush to change the clock to work in the US: Apparently, buying a teasmade, tax free, was a regular thing for Americans who had got used to starting the day with a cup of builders!
Sorry AC oulput, not DC, I just re-read, I can't find one of those - still looking!