Hii, I was planning on getting the samsung galaxy s4 i9505 (specs-http://www.gsmarena.com/samsung_i9505_galaxy_s4-5371.php)version, however I happened to come across the newer i9506 version (heres the specs-http://www.gsmarena.com/samsung_i9506_galaxy_s4-5542.php) with the differerence that it has a faster processor with a updated graphics processor and chipset. Now I want the i9506 version. my question is, because its LTE+ or whatever and each version has differnt frequesnices and stuff, will the i9506 work in the UK!? on a 4g frequency, in other words will I able to use the i9506 with a 4g sim in the UK or a 3g sim???? i dont know about all this LTE, frequency stuff, please helppp?
Also are these sites legit, as i don't want to order it and ut comes back in chinese or for it to be fake

????
Buy Samsung Galaxy S4 i9506 4G LTE 16GB Unlocked Phone-White | TipTopElectronics UK Samsung Galaxy S4 Plus i9506 4G LTE | MobiCity UK Buy Samsung GALAXY S4 4G+ (16GB) - White Frost
If not does anyone know of a site that is legit and fine and if you can get this phone in a 32gb version?