By your mention of Ferry Morse brand, I'm assuming you're talking about growing from seeds. All three germinates better with bottom heat 75~80Ã‚ÂºF, even a warmer for cayenne like Sage Hermit said, but Collard is a cool weather crop and will want to grow in cooler temp after sprouting. Technically, you could even direct seed the collard outside now (but it would take about 2 weeks to germinate in the cold). With heat, tomatoes and collards should germinate in about 3~7 days, cayenne more like 10~14 days.
I usually mix my own soil mix of 1/3 compost, 1/3 good garden soil and 1/3 sand. BUT you need to know what your seedlings are going to look like. I pluck out any weed seed sprouts. You might consider buying a small amount of potting soil and plant a control sample so you know which seedling is which.
Are you asking for variety recommendation? Why would you not consider flavor? Most of the time, the more flavorful they are, more nutritious they are too. I think you'll find plenty of tomato recommendations here if you use the "Search the Forum" function. Hot Pepper recommendations abound too, not necessarily just Cayenne. Collard? Hmm... I like the Dinosaur Kale
(Lucinato Kale) -- EXTREMELY cold hardy and grows right through winter snow. Very very dark green too, which speaks for nutrition levels. The one I have is an Heirloom variety from Southern Exposure Seed Exchange.
HUH. I just realized *I*m talking about KALE. Have not grown collard before so ignore my previous growing suggestions.
Let's wait for someone else who knows about how to grow COLLARDS.