I wouldn't break my neck to move the veggies in another mix into the 5:1:1 mix this year unless you're really concerned about your chances of being satisfied with your efforts. I would though, encourage you to read the information in the 'Water Movement' thread so you're better able to understand and deal with any effects of growing in the more water-retentive soils. Forewarned is forearmed.

I use the 5:1:1 mix for all my veggies and annual plantings and the gritty mix for anything I expect to be in the same soil for 2 or more growth cycles. How easy/difficult it is to get the materials sort of depends on where you live and how resourceful you are. There are several threads that address 'where to find' issues that you might want to look at for ideas.

Al