Oil question

[Quaser]

Hiya

I need to do a oil change for 2 polo's(2002 70k town cars mostly with a motorway run every 2 weeks or so) where the oil recommendation is 5w30 fully synthetic.

Now this oil comes in at around £30 for 4 litres, but the local maccess has an offer on 5w30 semi synthetic at £9.99+vat or 5w40 fully syth at £10.99+vat.

Are any of these suitable and what issues would i face if choosing either alternative?

Q