you know, the first time i went to the IT, i went there with my desktop. and they asked me about manufacturer. and i told them that there are a lot of parts from couple of companies.
then they said "we can only help with DELL or HP." and didn't even try to look at my machine. weird.
Well that is pretty weird considering the fact that a DELL or HP laptop doesn't solely have DELL or HP components. But there are many IT departments everywhere, there is no need to solely rely on your school's IT department. For Example here in Groningen in The Netherlands, I have about 8 IT/PC shops/workcenters in the center of town. Usually they can fix any issues for a cheap price.
Don't let your choice boil down to a certain thing just because your school thinks that because they have a deal with HP or DELL, they can decide what to repair or not. There is a multitude of good and reliable IT shops/workcenters in every town that can help you out!
I personally have build my own Tower Desktop with the help of Linus's Tech Tips and other YouTube channels. Let me link you a few that have a multitude of laptop builds that might suit your needs for a nice price!
JayzTwoCents
A reliable pc enthousiast that gives non biased reviews and shows you how to build stuff, including laptop reviews
https://www.youtube.com/user/Jayztwocents
LinusTechTips
Although he is a little biased towards his sponsors (mainly sites that sell stuff cheap), he does give good reviews about laptops.
https://www.youtube.com/user/LinusTechTips
HardWareCanucks
Another channel I visit regularly. They have a lot of laptop reviews, non biased and very critical towards performance and bang for your buck!
https://www.youtube.com/user/HardwareCanucks
Just search laptop in any of those channels and go and look at the goodies and reviews.