In my opinion, 10Gb for a 50 user network is overkill, unless they are all running something like CAD workstations, and pulling huge files all over the place. It will cost a lot to implement, and is unlikely to be necessary.
For almost all office environments 10/100 to the desktop, and gigabit uplinks are more than sufficient. Most of the processing is done on the desktop machine, so the network doesn’t take too large a hit. If you need to, you could use link aggregation and link two or more gigabit connections together but I am certain that none of the users will need more than 100Mbps to the desk.
The choice of switches, depends a lot on the grography of the office layout. If the cabling all comes to a central point, then go for a single larger switch, with redundancy, like a Cisco 4506 or even a 6500 (if you have a large budget). It is is more spread out, then go for 24 port switches with at least 2 gigabit uplinks and put in a larger central switch, with all gigabit interfaces, where the servers are located. Connect all servers at gigabit, and it is probably beneficial to give the main servers an aggregated link as well, this will improve the throughput. Use VLANs for each department, but that does mean you will need a L3 switch in there somewhere, on the core/server switch would seem to be the obvious choice.
I assume the branch office is in another County not Country? If it can be provided by the same Telco, then the price is probably OK, a T1 between two countries is usually VERY expensive. For either of these you should look at alternatives such as Frame-Relay or MPLS offerings from the Telco. VPN is a possibility, but it depends on how the database is accessed as to whether this has sufficient bandwidth.
The Internet connection, depends on the branch office connection type, and how much the office workers will use it. It also depends on what the service provider can offer in that area. It is a bit of a guess on this one, but I doubt they will need a T1 unless they are hosting a lot of remote users from the Internet. Go for a fast cable Internet if you can, which will probably be faster down than the T1, and about half speed up, which again should be enough.
The bottom line is that you know the customer, so are in a better position to make these decisions. The above information should give you something to think about in the design of the network.