yeah, window s8 is MUCH better with a start button added (there is an official Windows start button update, but its crap), I use this one at work and we use it on all our work PCs - no trouble at all with it
http://www.classicshell.net/
so yeah, you could go for a lower spec machine and upgrade later BUT you really ought to check what spec RAm is in the PC, and then go to Crucial.com and find out how much an upgrade will be. As said, you want as much RAm as possible. You will be able to upgrade the CPU subject to the Motherboard spec, so don't worry too much about that. If you find the dedicated graphics isn't up to scratch, easy, just buy a dedicated graphics card, £50, and slot it in, easy, plus your resident IT guys on here are on hand to help you out :thumbs