Texecom will do that, also Siemens / Vanderbilt SPC.
I don't know much about the Texe options but can confirm the Vanderbilt has 'proper' door access type options and setup, it's not just an afterthought add-on to an intruder alarm,
also there are a choice of door readers and these are taken from the same range as Vanderbilts 'standalone' access products. Also the SPC has a proper 'door controller' module,
though I think the Texe now does too, so you can localise connections.
For a single door with that few employees, Scantronic iON would also do it although with far less flexibility over differentiating 'door' and 'alarm' users, but does have an handy built
in IP server to manage the users like the Vanderbilt SPC - for the Texecom this is an option.
I don't know what stage your building is at but these things really do need to be considered very early on if possible. I assume you're based in Sussex?