You can use DB2 V8 ESE ... 5 user license for DB2 Connect is included in the ESE License fee ...
There is only one fixpack, be it client or server, you will have to install the same set of fixes only ... The link to clients you see on the fixpak page is the full installation of the client with the fix applied ... So, download the FP tarfile and use the same tar file for ESE, PE , Connect, Clients etc ...
HTH
Sathyaram