Checked the gateway's part number of my Octavia as i decided to buy a Bolero and see if it works or not but the part number of the gateway is 1K0907530F.I've been told here on some other post that I need to update to a K or later version to avoid battery drain issues ??? ... Also is this a matter of having to re code the thing or is it just a matter of plugging it only ?.

I had a RevF gateway work successfully with a Bolero in my old MY06 vRS.

But if you do need one, yes - it's a replacement unit which you'll need to buy, to swap out the older one. If you're going to do it, you might as well get the latest AD revision. These are available from a reputable eBay seller for around £85.