If you use Foliage-Pro 9-3-6, MG or Peters 24-8-19, or MG 12-4-8 and add dolomitic lime to your soil when you make it - you shouldn't have to be too concerned about the minor elements. If you DO decide to use a micro-nutrient supplement, Microblast by Earth Juice is good and easy to come by. I use Micromax and STEM - not so easy to come by in small quantities (under 50 lbs), but often chosen for commercial applications, in large part because of its efficacy and low 'per dose' price.

Al

Assuming you're buying potting soil for the first time, why are you worried about nutritients so soon? They tend to come with all the nutrients needed for the first 3-4 months.

Reading you post shows you will not be buying potting mix but rather making your ow.
So it will need the fert and micros if you choose .
I use the miracle grow myself and add the dolamite lime ,this seems to work ok for me