You have to register there to be able to download the covers - though they are usually ‘decent to very high quality’ covers and have their own forums too.
Don’t you have to pay in order to download uncompressed covers on that site? It’s ridiculous.
I think they have a Gold Membership thing for $10 annually where you can download any of the full size artwork there as often as you want (think the $10 is to help cover costs of hosting all the stuff they have there). Though for regular members you can download them for free (just in a smaller resolution/size).
Those covers above are in 6406x4293 for Gold Members - so IF* you only get half of that size for regular free members they’re still good quality covers for a 5 minute signup and browse around (and you may like it and stick around etc).
(* - I don’t know if you actually do get half size resolution - or smaller or larger than half sizes for free members).
The FAQ on there probably has more info on it - http://www.freecovers.net/faq
Alright, thanks for the info.