Your Discover, NFCU and Wayfair cards are all growers.
Instead of asking which cards can you get approved for that will grow, it would be better to decide which cards or types of cards you want and go from there.
For example, I could suggest Pottery Barn cc, which you'd probably get approved for and will grow, but it's useless if you don't shop there.
Well you could try for the PP MC for 2% on everything. Thats a all around card. Sync grows with responsible use.
I think you should garden as it stands and be patient for NFCU and Discover to grow.
Not getting additional inquiries and new accounts will really help this endeavor. I had $25k revolving with NFCU a little more than 2 years post discharge, and just over $50k today. My Discover is at $13k now.