where to buy custom windows I can install myself

I just installed a new pre-hung fiberglass entry door, to go from my basement to the outside. I went with fiberglass due to the inclement weather we get year round. Before I bought the door I measured the old door and found it to be a 30", which, much to my dismay, meant I had to special order the door as, nobody carried that size for an entry door. No problem, I went to Lowes and ordered a 30x80" door, but when I removed the old door I found that it was 79", not 80". I didn't want to rip out the walls and replace the header so I disassembled the top of the door frame and cut off an inch. It was a hassle but much less work than the alternative. I didn't think cutting an inch off the top of the door would be a problem, as I thought it was wood around the perimiter, but I found out different and now I have exposed the foam core. :wall: Does anybody know if this will be a problem for me sometime down the road? Thanks...RC

We have finally tired of the leaky double hung windows in our 100yo home in Canada. The installer is putting in 10 quality vinyl windows. (I checked them on the net and they seem fine) My question is that the installer, when he was here to do the final measurements, indicated that taking out the roller wheels that the sash cord travelled on was too time consuming so he just planned to hammer them into the opening that the counterweight travelled in. I've worked on these windows before and I know this will shatter the side of the frame. Is this smart? I know that he plans to cover the existing outside frame in aluminum to hide the breaks but it still seems that a lot of cold will get in. Also I asked him if the big hollow that the counterweights travelled in would be filled with insulation of any type. He said that it wasn't neccessary. I don't believe him. That is a huge space on either side of each window. Any suggestions or am I being paranoid? Thanks, Alan