I'm having the same problem. The only ones I can find are Action Replay files, even though I know you can just put a .sav file onto your R4DS and play that file without using any action replay or 3 in 1 mumbo jumbo. I want a .sav which works just with the R4DS..
Anywho, I couldn't find one so I'm not trying to get 999,999,999 bells by time-skipping my DS. I've spent about 16 hours overall doing this already and so far I've only gotten 10million bells.
Anywho, if all you want is all house upgrades and gold tools, just change your DS time to New years day and put all your money in the bank.. Then just keep changing the time by a year or 5 years at a time and once you have about 2 million you can get all house upgrades, all nook's store upgrades and all gold tools.
The tools aren't hard to get....
Anywho if you're too lazy to do all that, once I reach 999,999,999 bells the slow way I'll upload a .sav which I used no form of cheating other than time skipping to get, and it should work with your R4DS.
EDIT: Oh... Oh... OH DEAR!!! I'M SO SORRY FOR BUMPING A 2007 THREAD!!! I FOUND IT IN GOOGLE AND DIDN'T REALISE!!!! O.O AHH!
Anywho I would still quite like to know myself.. I saw another thread on this forum which had a link to a generator for turning .duc and all the animal crossing save games from this site into .savs which work with the R4DS, but the conversion didn't work on my R4.. Help please??