Hi LC - first congratulations on a good choice. Second, there is a recent post that discussed the options as you are considering. My short answer is to order all options!
Build time? ..... that one will yield a lot of answers but it depends on if your 10 hrs is in a block or scattered, how familiar you are with this type of work, what sort of set up you have, how much support you have etc. But I am at the unskilled/inexperienced end of the builder spectrum and put in more than 10hrs/week and it took me 2 years. There will be more opinions!
Good luck and welcome - you wont regret the choice.
cheers
r