Cindi, Palatine's roses are much nicer than Regan's roses, but both places are good sources. Regan has a much bigger selection. For one thing, Regan still carries David Austin roses, whereas Palatine stopped carrying Austins a few years ago.
Lyn, a well-established Liquidambar tree shouldn't have any trouble dealing with drought. Are yours young trees? I had a huge Liquidambar on my property when I bought my house, but I got rid of it a few years later when it lifted the corner of my foundation. They really don't belong within 25 feet of a building.
