Hi,
I am having one installed as I type this.
Click on the site below, and hit porchs gallery, the first example, (Site is slow)
This is very similiar to my one being put in, I think by your description yours is similiar too, (existing roof) I went for a vent over door rather than having the window at side.
http://www.windowmasters.ie/index-3.html
I got 3 quotes,
€1950 supply & fit (but base done by me) or €150 more for base too
€1750 supply & fit (but base done by me) or €200 more for base too
€1600 supply & fit & base done too.
I was waiting about 3 weeks from date of ordering to having it installed.
So €1600 option being put in, and so far it looks well. This will hopefully reduce my heat loss through existing wooden front door.
BTW the site above was the most expensive quote for my job.
I'll tile floor myself.
Also [broken link removed] ( I found this site last night as I was looking for safety stickers for the new glass) They have frosted circles that are similar on any public door entrance to comply with glazing warning requirements. I think their prices are reasonable. Last thing you want is someone to run through your new door and hurt themselves.