Priorities, sort by & colours

Priorities in their current form just don't work for us. I'd like to request
1) The ticket view to be arranged by priority
2) If possible, custom priorities / priority colours would be helpful too

Example only
For our workflow, I would like priorities to be coloured as follows:
No Priority Set - White
Urgent - Red
High - Orange
Medium - Yellow
Low - Green
Very Low - Blue