I'll suggest what I am going to personally start with as I am also very interested and impressed with this brand. Vitamin C is fast becoming one of the most recommended ingredients we should use on our skin by many dermatologists (behind retinol) so I am opting to begin with NCN's C serum. I have long been a proponent of vitamin C after researching it's benefits some years back.
I am a bit torn between the DNA serum and the Copper Peptide ......... the Copper peptide because I want to start derma rolling and know that can be used right after rolling and the DNA because I have read some benefits of combining that with the C serum. I would suggest if you are not using any type of retinol product, you might want to consider the C and the trans retinol. I currently have a retinol product I use so won't order NCN's trans retinol until I finish with my current one.
Many NCN users are very interested in the Volu-lift cream which you said you have already decided on. It has been mentioned here a few times and I believe a few have also ordered it. You'll have to post what you think about it after using it.
You really can't go wrong with any of those you've selected, to be honest. Nancy is usually very good at responding to emails according to many here so I would give her another day to get back to you with her recommendations.
The C serum will definitely help with firming and age spots as well as over-all skin texture.
BTW, a bit OT for a moment but I love the area where you reside. I have many very fond memories of Lebanon, Lancaster and surrounding vicinities. Have you ever heard of Mt Gretna? My sister lived in Gretna (and initially Lebanon) so I used to visit a lot. We were very close and sadly she died while only in her 30's (which was quite some time ago now) so have only had a few occasions to visit again since (niece and nephew's wedding, gradations and the like) Absolutely a lovely area!
Good luck deciding and hope I didn't add any confusion to your decision making!! 