I adore
Matthias. Thats my favourite spelling cause it looks the most complete to me and I worry about
Mattias being more prone to the nn
Matt, which I loathe. But I do like all the spellings of it. I prn. it the same way as you, in terms of spelling I think
Matias is the most straight forward pronounciation wise.
I plan on using
Matthias as a middle name for either a first or second son- my combo atm is
Oscar Matthias. I love the meaning and the sound of the name.
Andreas and
Mattias sound good for brothers. I wouldn't worry too much about nn's, they usually just develope once a child is here. But I can totally understand wanting to avoid
Matt (yuck) by having another nn in place from the start. How about Tias? (tee-es). Way better than
Matt.
Love the sibset.
Cecily is a great name. I don't think sibsets have to match at all so I'm all for mixing.