Greetings, new member here looking for affirmation and/or suggestions on my equipment choices; prior to purchase?

Sorry for the long post. I have been reading posts here and watching You Tube videos for a while and have determined that I want to join the cool kids in the hammock camping world.

About me: I am 6’ tall and weigh 200lbs. I have experience camping in a camper, but no longer have the camper. It has been forever ago since I tent camped. I have a cheap hammock I picked up at Sam’s Club a while back for lounging in, but have not spent an entire night in it. I recently decided I would like to do some backpacking/bikepacking and believe my 53 year-old body would prefer a hammock over a pad and the ground. I hike regularly, 15-20+ miles over a weekend is not a problem. I bike more and 60-70 mile days are doable – planning the C&O/GAP trail from Pittsburgh to DC in the late spring.

I live in Kentucky and most of my backpacking trips will be in the Red River Gorge. The average lows in the winter are in the 20s*F; although we may see single digits occasionally. I do not plan to do trips when the forecast is calling for extremes; and I plan on sticking to above freezing temps, although I know I need to be prepared for the unexpected.

I am really just wanting to know if my choices are good ones, or are there better options that I may have missed? I am trying to stay as low cost as possible to start and will upgrade down the road since I need pretty much everything for backpacking and do not have unlimited funds to purchase top of the line equipment all at once.

The equipment I currently have is:
15*F sleeping bag
60L backpack

My planned equipment: (purchasing in the next few weeks)

DIY gathered end 11’ hammock – (My aunt is a seamstress and has agreed to do the sewing) I plan on camping with my ~40lb dog in the hammock at times. I contacted Ripstop by the Roll with questions about material and they suggested 1.7 oz MTN XL Hybrid Ripstop Nylon for extra durability with the dog. Sound good? Or would anyone suggest a different material? As for hanging the hammock I am considering straps, whoopie slings for the suspension/ridgeline and hardware from Dutchware.

Tarp – I considered a DIY tarp to save $$, but after seeing many good reviews on the Onewind 12’ hammock tarp I think I will start with that and possibly attempt a DIY tarp later down the road. I like the ability to close off the tarp.

Under quilt – I believe this is probably the most important piece of the system and where money is well spent. I am currently considering the HG Economy Incubator 20*F for cold weather camping and pairing it with my 15*F bag. The overfill option - is it worth it? And, if so, how much overfill? For warmer weather (45*F+) I think I will just pick up a cheap Amazon 40*F synthetic under quilt or do an Apex synthetic DIY under quilt? Any suggestions on other under quilts to look at in the <$300 range to handle my cold weather needs? Will the 20*F quilt be enough when combined with my 15*F bag if temps were to drop into the low 20s*F or high teens? I will have sufficient clothing layers to add based on weather predictions.

Top Quilt – I plan to use my 15*F bag until I decide what to do for warmer weather. I will either purchase a warmer weather bag or top quilt later down the road.

I plan to test the setup in my backyard or car camping before heading out into woods.

Thanks in advance, I feel like I have already learned a lot from this forum and a lot of my choices are based on posts I have read on here.