cptTHC

Yep, save up for either an E&L or LCT, buy cheap buy twice.  G&G are decent enough but their AKs arent anything to write home about.  There is a reason everyone buys E&L or LCT.....

Gunfire has some decent AKs in your price range
 
https://gunfire.com/en/products/els-74un-subcarbine-replica-gen-2-1152204225.html
https://gunfire.com/en/products/els-74n-assault-rifle-replica-gen-2-1152202731.html
 
For a bit more you can get an LCT  AKM
 
https://www.fire-support.co.uk/product/lct-akm-nv-airsoft-gun-aeg
 
Or AK74
https://www.fire-support.co.uk/product/lct-lcks74-nv-aeg-airsoft-gun

Personally, I would pick up the E&L AK74 for that price.
 
 

The G&G AK74 you linked is fine perfectly skirmishable however you are forced to use g&g propriety battery handguard system so if you want spare battery you have to buy their battery handguard like this one https://eagle6.co.uk/shop/catalog/product/view/id/5641/s/g-g-li-po-handguard-battery-for-gk74m-gks74-7-4v-1000mah/
 
This means you can not customise it with lower rails system if you wanted to add attachment such as lights, foregrips etc as for mag compatibility most major brands should work but they may need some fettling on the rear mag catch to fit properly.
 
Personally I would save for the LCT better overall more options for customisations and not reliant on proprietary parts. There is also E&l range of AKs particularly from gunfire which are very good in my opinion and are quite well priced: https://gunfire.com/en/products/els-74-mn-assault-rifle-replica-gen-2-1152202735.html
https://gunfire.com/en/products/el-74-mn-assault-rifle-replica-gen-2-1152202736.html
 
One caveat to note is that it comes from Poland at around 400fps so you will need to downgrade for the UK but that's fairly easy due to E&l QC gearbox spring