I know what you mean about the s's - it would bother me a bit too - but in reality how many times would you be saying the two together? I think both names are lovely - one of my ds is called one of them and the other was a close second! What about Samuel Tobias? Oh and I think Tommy and Toby sound fine together, but possibly not Thomas and Tobias.....
I don't like Thomas and Tobias together (think xmas cards!). Tommy and Toby not bad. I guess they will end up Thomas (or Tom) and Toby anyway as Thomas is easier to say in full version. Thomas and Toby is fine.
I am down to these 2 names as my final options so was interested in this thread. I don't think they are too similar sounding but much prefer Toby to Tobias - plus dh has grudgingly agreed to Toby but will not have tobias for some reason.
we're thinking Toby alexander.
Samual Tobias sounds nice but i'm not a samuel person tbh.