Thanks to everyone who has tipped and commented. Just a couple of pointers regarding the 'Building the QT Wallet' stage:

• If you cannot clone the Denarius github files, you may need to install git first by entering this into terminal:

sudo apt-get install git

• If you run into trouble making the swapfile (step 2), you may need to do those steps but put 'sudo' at the start of each command, eg.

sudo dd if=/dev/zero of=swapfile bs=1M count=4000
sudo chmod 0600 swapfile
sudo mkswap swapfile

• If when doing step 4 you receive an error like 'qmake cannot execute: no such file or directory', then you need to add in an 'export' step to make sure Ubuntu uses QT5 for building the wallet:

cd denarius
export QT_SELECT=qt5
qmake "USE_UPNP=1" "USE_QRCODE=1" denarius-qt.pro
make –j4

Cheers!