A bow window is in the shape of a bow with a gentle curve on the outside. A Bay window has three different angles and got it’s name from houses on the waterfront being built with projected windows with smaller windows on the side so they could look out up and down the bay. They are not the same.
Pella & Andersen, Marvin, Peachtree are all top of the line. Plan on $1800-$3,000 depending on the size.
Go to your local lumber center and get some references of contractors from the commercial sales dept. Talk to friends and neighbors who you see have had some remodeling done in the past.
Companies that specialize in just windows and doors will try to push THEIR brand of windows. If you contract through a contractor he/she will install any window brand you select.
Pella has their own “Pella window store” yellow pages. They will also come out and measure your window.
You want insulated glass – people still refer to this as “Thermopane which went out 15 years ago.
There are thousands of window companies, but only a handful that have been around over 30 years or more. Don’t fooll yourself – there is a reason why some windows cost twice as much as others – they are built better and have a better company standing behind the warranty.
We have installed many bay and bow windows – so expect to pay a total cost installed of $3,500 – $5,000 depending on the window size and the ease of installation. Go with vinyl or aluminum clad wood window in the brands i suggested.
Good Luck

It is often called a ‘bay’ window and is best when pre-fabricated. Pre-fab construction materials are superior in durability as they are made to endure the transportation. Your biggest challenge lies in choosing the best installer.

I have recently replaced windows and was very satisfied with Champion windows manufactured in Denver, Colorado after much research and the advice of a local consumer advocate, Tom Martino.

The brand of window will be highly dependent on your geographical area, but these tips will help get you started. You will be equally satisfied with whichever brand gives you the style/color that you are looking for.

1) Anderson & Pella windows are the ‘gold’ standard
2) Double pane is ideal, Triple pane is a gimmick.
3) Fill the double pane with Argon gas, if they are made locally, otherwise it can be a gimmick.
4) Choose the UV coating on the window for significant home comfort and to protect curtains and furniture from sun damage.

Try three to five estimates on the labor selection and ask them to bring photos and references of previous similar installations. Fortunately you don’t have to worry about price, but you will quickly discover which contractors are not timely and communicative.

Good luck on your project!