Hung out on the excellent
mig welding forums for a while before going for the GYS SmartMIG 162. I would have liked a Portamig but whilst I could justify the £380, I couldn't the Portamig 165 price of £530. I do regret that decision a tiny bit, as the GYS can only go down to 30 amps but the Portamig 15 amps, so the latter is far less likely to blow a hole in thin steel. Though I must hasten to say that SmartMIG is an excellent piece of kit that will give long service, and unlike Clarke welders it is modular so you can swap out the torch with another, and the all-important wire feed mechanism is very well made.
I think the TL;DR is that as a total beginner I went with the kit that was most likely to cover up my ineptitude, and spent a little more on the GYS than the Machinemart basic.
Edit: Gas bought from Motor Parts Direct, rent-free bottle of CO2/Argon mix from SGS Gasses. Did try flux core, a lot of splatter and fumes but essential if welding outdoors and it's windy, personally preferred the gas.