It depends on what you need to do--if it's just manipulating single images, LR desktop is fine --I use Photoshop CC because I do extensive layering of multiple images in creative ways, eliminating backgrounds on portraits, etc. and the tools like quick selection in Photoshop let me do this--I guess there are other good image processing programs out there--if you subscribe to the Adobe service, you get both the Photoshop and Lightroom apps, which is terrific!!

I have a D750 and all kind of lenses--when I go somewhere I take them in my big camera bag and use what I need as I go along--I've also gone hiking with the camera and a 28-300 lens. I'm no youngster, but I don't have any trouble with the weight remember in the old days people used to go out in the wilderness with bulky view cameras, so we have it relatively good!!

I have had a Nikon D750 for a couple of years and absolutely love it--full feature set, works flawlessly and for what you get, the price is right--highly recommended!

I've been using Photoshop for the last 20 years and finds that it does everything I need in the image processing dept. --but use what you're comfortable with---it takes time to really learn the resources one of these programs have to deal with your images.

We have lived in Scottsdale and Phoenix for years--"Old Town" and the civic center in the heart of Scottsdale are fun to visit and you can pick up a map of the area --there are some moderate hiking activities in the area- like Camelback Mountain, etc. the tourist folks in old town can help you with those--just driving around Scottsdale is fun--also, heading up north on Scottsdale Road will take you up to Cave Creek, a picturesque "western town" --also worth seeing within easy driving distance --restaurants abound in the area, (we like Los Olivos near old town for good Mexican food) depending on your tastes and budget --hope this helps!!

I recently purchased a Sigma 150-600 Contemporary zoom for Nikon and it is totally outstanding and produces sharp contrasty images throughout it's zoom range -I would recommend this one to you!!

I have a Nikon D750 and several zoom lenses from Nikon and Sigma --they all seem fine to me; I just got the new Sigma Contemporary
150-600 zoom which is razor sharp throughout its range, and I can even use it handheld with fine results!!