For Pinus taeda, use the assembly GCA_000404065.2 ? The genome.fna.gz is 5.3 GB compressed and should load by FTP. ftp://ftp.ncbi.nlm.nih.gov/genomes/all/GCA_000404065.2_Ptaeda1.01
For Picea glauca, use the assembly GCA_000411955.5 ? The genome.fna.gz is 5.5 GB compressed and should load by FTP. ftp://ftp.ncbi.nlm.nih.gov/genomes/all/GCA_000411955.5_PG29_v4.1
Both are still scaffold-level assemblies and may or may not function optimally with certain tools, but you can test this out. If the load times out when using an FTP client (Filezilla is one), it can be resumed to finish the transfer.
I added both to the list of genomes to consider adding. This will not be immediate. https://github.com/galaxyproject/galaxy/issues/1470
Custom reference genome help link below. Be sure to note the chromosome naming advice for the fasta. In short, keep these very simple by using only an alphanumeric plus underscores identifier, with no description content. https://wiki.galaxyproject.org/Support#Custom_reference_genome