someone is going to buy me some effect. If I ask him to buy me stomp boxes it would cost a lot so to lessen some expenses I decided to choose a multi effect pedal. what would be the best pedal to recommend? im in to metal , steve vai sound, and SRV

what do you think about
Zoom 707II
Boss ME-50
Korg - AX10G Guitar Modeling Pedal
Boss GX700 Effects Processor