Some people find an electric guitar easier to play as the strings can require less pressure to fret, but you do have to factor in the price of an amp and leads as well. IF you do decide to go down that route, Thomann do some very good bundle deals on guitar an amp. I got a telecaster style guitar and an amp for £150 and am really happy with it (the guitar is great, the amp is just ok, but will do for now). Justin Guitar's lessons are really good, so I'd say stick at them. Marty Music does some good ones too.