The major reason computer technology deployments for K-12 education (in the US at least..)and failed to deliver on it's promises while becoming a black hole of spending in the 90s and early 2000's, is that the approach was similar to the one you describe here.
Back then, we gave teachers and administrators the latest, greatest technology and expected them to figure out how to use it in order to make instruction better. Some teachers did just that, but they were few and far between. These early adopters created pockets of technology and inconsistency/inequality of instruction across the school landscape. In the worst cases, the technology sat gathering dust in the classroom closet.
Several years ago I participated in a large-scale Gates Foundation grant to study various models of instruction and gather measurable data about those models. ( Before you jump up-and-down about Micro$oft dealing Windows to our kids, you should know that of the 9 million in grant funding, only 10% could be spent on technology... the majority had to be used to study the instructional outcomes of the various school models.)
As the result of that study we found a number of proven technologies and techniques that helped to enhance the learning experience.
1) Before you buy a single piece of Tek, you need an instructional technology plan that will show how the equipment and software that you choose will create the instructional outcomes you want. Results MUST be measurable so that you can share them with the public (partial to justify the expense...) and instructional staff so that you can build and refine your techniques. The plan should be at least 3 years in depth and be flexible enough to absorb changes in administration and instructional staff. If you do not do this first, all the tek in the world wont help you educate kids.
2) Develop a support plan and a refresh cycle. This is the IT side of the house. You plan should include long term training both for new staff and a constant refreshers for existing staff. You want admin computing (see #3 below ) to be a no-brainier so you can concentrate your resources on the instructional side of the house.
3) Deploy a standardized technology to instructors and administrators in order to cover the rote administrative tasks like grading, email, communication, Internet research, and word processing. Thin client works very well for this. It's robust and consistent.
4) No Classroom Computers in Grades K-3: Children at these ages need to focus on interpersonal and cognitive skills. Computer Technology at this level has been shown in many studies to decrease the learning process.
5) Deploy Smartboards, LCD Projectors, a Presentation PC with an attached "Elmo", and classroom sound amplification system (such as the "FrontRow" product). Of all this equipment, the piece that will make the most difference is the amplification system. This technology has been proven time and time again to increase student learning/comprehension and at the same time, reduce teacher absenteeism.
6) Consider learning labs and mobile devices such as tablets and laptop carts, if they fit into your instructional technology and support plans and maximize your available resources.
And just some tips from my own years of experience in edTek:
-Break the low voltage data infrastructure wiring out from the general contractor who is building your new school. Generals don't understand the big-picture of data. Be sure that the IT staff is involved in the deployment and design of your plant.
-Don't skimp on power outlets and data jacks!
-Laptop carts can be very heavy when fully loaded. If you use them, go with more small ones with fewer laptops.
-If you engage a consultant(s) to oversee your tek deployment, be sure they have lots of experience with school technology. Business folks often don't understand the differences that exist between the private sector and education.
Don't fret over the Windows/Mac/Linux issue for instruction. If your teachers are educated, your kids will get it. Kids are sharp.
-Desktops last twice as long and cost half as much as laptops. Be sure you buy top line business stuff and don't skimp by buying "consumer" models.
-Engage your community in developing your tek plans.
-Don't buy into the "one laptop per child" model. Many independent studies show that you get more bang for your educational buck making sure your students have access to a good breakfast and lunch program. Nutrition powers learning.
-Don't skimp on ongoing training.
So, remember; Make every choice fit your tek plan and drive your deployment toward those measured results. Don't be afraid to ask questions and try new pilot programs if they fit your model.
Good luck !
Time-sharing is the junk-mail part of the computer business. -- H.R.J. Grosch (attributed)