As a rule of clear expression, things that people compare should be directly comparable. Use the same format for both.
Therefore regardless of whether you'd write "10 hours" or "ten hours", you should write "17 hours 30 minutes or 10 hours 43 minutes" not "17 hours 30 minutes or ten hours 43 minutes".
Of course any combination is grammatically correct, this is therefore a question of style. Someone else might put more priority on consistently writing "ten" than they do on the internal consistency of the sentence.
Personally I don't think I'd write "ten hours 43 minutes" anyway. Once I start using numerals in a sentence, I stick with them. Exceptions occur where the quantities aren't "the same thing". So:
I have 3 donuts, my colleague has 12.
Two of the three of us are human, the other one is 12 squirrels
standing on each others' shoulders in a long coat.