@Gaz - Had quite a few quotes and head is spinning from the options now... VeryPC, CCS, Dell, Downtown Computers (Local company who came in very competitively!).
@localzuk - Think I will have a word with SLT and push the SSD idea. Cost is around £30 more per machine but I agree that it is a worthwhile spend long term.
Seagate Momentus ST9750420AS - Hard drive - 750 GB - internal - 2.5" - SATA-3...: Amazon.co.uk: Computers & Accessories
It seems that these are "Sold by X, fulfilled by Amazon" deals (which are what the two I've just bought were), so it would seem that Amazon is acting as a wholesaler for resellers here - the wholesale (and, you'd hope, bulk system-builder) price must be a bit lower.
The part code you're looking for is:
ST750LX003 (Momentus XT Hybrid Drive | Seagate)
To the original topic. Be careful that you are not just digging yourself a hole, you may need to purchase less stations up front but buying a solution that will cause problems in future is just causing yourself problems. A 60GB SSD and i3 will work well for a couple of years as long as you have limited software usage. Five years though is a long time, we get mid level i5's to get that kind of longevity in a primary school.
We would love to use SSDs here but in NZ at least the cost to use them is just way to high so we are stuck with magnetic media for the time being.
To sum up, don't use the money to dig yourself into a hole, if you need to buy less or simply tell them that they are insane to expect that much for the budget provided. If you do have to go i3 - personal opinion and experience - stay clear of Intel motherboards, the slowest implementation of i3's I have ever seen that put me off them for a couple of years.
I would try for 120GB SSDs and i5 if possible, five years is a very long time in technology terms and it is a very long time to listen to the moaning when it proves limiting.