you could do worse than an innokin itaste vv, i have one as my backup and have had two friends buy them since. its small, light, has variable voltage, can be charged with the old pin style nokia chargers and can be vaped while charging, its got an ego/510 connection so fits most all clearos/cartos/attys and bought from vapour room with the discount code here can be has with one ce4 and one itidy clearo for just under £30 delivered, that leaves you plenty of room for juice