Folks, according to Fatmir's profile he is located in "Pristina, Kosovo". That could result in some challenges relative to import fees, VAT, etc.
I do agree though that you should purchase the 24-hour FARS unit w/Solar & UV sensors. It is a lot less expensive than adding the units later. PLUS, you cannot purchase the 24-hour FARS as an add-on afterwards. Davis only has a Daytime-only FARS unit as an add-on.
While it will take longer to get, save your money and then get what you really want. You WON'T be disappointed with any Davis unit.
When you do get your new unit doesn't hesitate to come back to this forum and ask questions, if you have any. The is a lot of expertise here.