The bitcoin daemon on the offline machine is used solely for signing transactions and is therefore run without a blockchain. The binary included in the Bitcoin Core release is just fine for this purpose. Binaries for your platform can be obtained here or here.

After installation, locate the bitcoind executable, place it on your execution path and start it with the command:

$ bitcoind -daemon -maxconnections=0

Note that in the absence of a blockchain the daemon starts very quickly and uses practically no CPU once running. Thus a low-powered computer such as a netbook can serve quite nicely as an offline machine for signing transactions.