J.
First, I would begin saving because these are both expensive projects and it is best to have the money before you begin. Plus, you should consider the age of your home in this matter because if your house has any lead paint on the walls and/or windows, you could be exposing your child to lead poisoning. If your house is older than 1978, I believe, it is pretty common to have lead paint. We want to do an addition, but we've got a 20 month old and another due in December. We've elected to wait five or six years, which will give us time to save and let the children's immune systems develop so they'll be less susceptible to lead.
As for where to look for windows, I like Andersen Renewal windows because you can get ones with the wood interiors. They are better made and don't look like trailer park windows. I prefer the operation of Andersen to Marvin and they do come in a bit cheaper than Marvin. Plus, you'll get a 15 year guarantee, which they are quite good about honoring. For window renewal, you'll be looking at $20,000 or more.
For cabinetry, I suggest Guyer's builders' supply because they carry higher end cabinets, which will last longer and have nice design sense. Cabinets alone will usually run you about another $20,000. Plus there is installation and countertops, along with any electrical, plumbing, permits, etc. I have been pleased with the appliances and service I received from Warner's Stellian.
For financing, have you approached your bank about a home equity loan? A home equity loan seems to be the best option since you'll get the tax break on the interest you pay.