Are there any specifications that you want in the shinies, for example no nicknames, competitive, untrained, etc...
I have some shinies I am willing to part with and can offer in exchange for your Dialga and maybe Thundurus.
Let me know and I will make a list of the ones I think might interest you.
Any kind of shiny is good for me, preferrably with no nicknames, but it doesn't truly matter to me :)