I don't know about you. I will not use a man-powered reel mower in my
1/4 acre property (7200 sq.ft. are lawn). In my opinion, your 1/2 acre
is just too much lawn for a reel mower. If I were you, I would either
get a gas-powered self-propelled mower, or even a riding mower (if I
get enough money).

You may want to check the soil type, and try to improve the soil
before plainting grass seeds. The soil in my lawn is very sandy and
cannot hold water that well (only 1/2" to 1" top soil in my front
lawn). I must water the lawn more often than I want ( ~$$~ --- flying
dollar bill). If I could start everything all over with, I would have
added much more top soil with plenty organic matters and compost and
such.

Although this is very tempting to add underground sprinkling system to
your property to ease the burden in watering the lawn, I suggest not
to do this right now. You need to spend some time in your house and
your garden/lawn. When you have spent one or two years in your new
house, you will form a plan in your mind as of what to do with your
garden and lawn. At that point, you may convert some lawn area into a
flower-garden or a vegetable-garden (1/2 acre is quite large to fit
many types of garden). Having underground sprinkling system already in
place may restrict your freedom in designing your garden. For now, you
may want to use water hoses and a timer and water different areas of
the lawn in alternate day.

One last thing, you may want to buy a book on lawn care, and keep it
in a convenient place for reference.

Hope this helps.

Jay Chan