On the GPS, the topo maps and land ownership are nice, but if I thought this was my only hunt out west in the foreseeable future, I would not spend the money on a new one. If you want a topomap, go to www.mytopo.com and you can custom design a topo map in any size imaginable to carry with you or leave at camp as a reference.
On boots, yes you will probably be hiking. Probably in snow. Probably in 20 degree or lower weather. Dress accordingly. I would suggest some insulation of some type. Besides good optics, boots are probably the second most important item to keep your hunt going smoothly. Cold feet or blistered feet will end a hunt or make you miserable.