To get all gig ports you would need to go with a 2960-S, so...
All prices are refurb/ebay/etc., brand new is 50-100% more in some cases.
48 Port 2960-S with LAN Base (WS-C2960S-48TS-L) - $1,800
24 Port 2960-S with LAN Base (WS-C2960S-24TS-L) $1,000
Now, 2960-S switches, if you want to stack them you also need the stacking module (one per switch) at $700 a piece. So for 8 switches (24 or 48 port, doesn't matter) you would pay $5,600 + cables to stack them, if you wanted to. PLUS, 2960 series has a max of 4 switches in a stack. So you would then need two stacks.
If you needed a larger stack, you could go to a 3750 (E or X), and get 9 switches per stack. Price goes up to $4k for a 48port or about $2k for a 24 port. All 10/100/1000 ports, includes stacking ports so no additional models. These are also layer3 switches (if you get the IP base software models).
So if you do not need to stack and do not need routing I would go with the 2960-S. That's also if you really need Gig on all ports.
If not then I would go with maybe a 2 3750's with IP base in a stack, and then connect regular 2960 switches to that. Then connect any Gig stuff (servers, etc) to the 3750's, and run the 3750's as your gateway.