Being pretty close or the same height (I'm 198 sm) and with the same wingspan I know very good about all the possibilities so as the troubles you face.
To tell the truth the diameter of my grip area was never my major concern but the length was. I should also add I'm from the country where the major billiard game is piramid and in spite of the fact I prefer playing, competing, teaching pool but I also have some experience with piramid.
Honestly my experience in piramid is a big plus and in certain ways it helped me a lot when it comes to pool.
When it comes to pool I've played with 60" Prather cue my teacher helped me to get for so many years ... till a few years ago my curiousity and some other interests motivated me to learn one more aspect concerning billiards - cue building. My interest to build the cues for myself according to my own preferences was one of the reasons.
So as I also have a cue for piramid it helped me to feel what cue's length I'm more comfortable with at a pool table.
In addition so as I'm teaching...coaching at our pool school in the university I graduated from I'm curious about everything concerning billiards ... including the cue-building development, the differences when it comes to their construction in different kinds of billiards and so on.
Due to my profession I have possibility to communicate with players, some cue-builders at my country to share some experience and I made really good friends with some...
Now with regards to the comments on such a long cue might be whippy and so on... I always wondered why it is in piramid in a game with the biggest and heaviest balls the most common specifications are something like this:
length =160 sm (around 63"); weight 25 oz; 12.8 - 13 mm at the tip; diameter at the middle (at the joint if even split) = 19 mm (0.75 or under); diameter at the butt end = 27-28 mm (1.07 - 1.1).
So in a game with the heaviest balls much longer and heavier cue is the slimmest comparing to other billiard games. I had some talk with my friend who builds exceptional piramid cues and asked about it ... The answer was pretty simple... He said it is just what most piramid players like the most.
So as it is not "ask cuemaker subforum" I won't go deep into all the details about constructions and so on used to achieve what one prefers...
To be short ... in my experience the biggest influence on how the cue performs has combination of the construction and the woods (materials) ... and of course the taper used.
The first cue I built for myself is a good example. It is 62" (even split). I had to say I like to experiment because that is how I learn. So my 31" full spliced butt built with such woods that if finished at those most common diameters it would be above 18 oz (butt only). I managed to get it at 15.95 oz with a balance I like but I had to pay some price for that ... experimenting with the taper and some more "tricks". Finally I got it very slim comparing to most standard length pool butts:
21.3 mm (0.84) at the joint, 25.9 (1.02) 15.5" after the joint, 30.6 mm (1.2) at the butt cap.
Long story short ... this long and slim cue turned out pretty damn stiff with the hit I just love. Might be I was just lucky

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Here is a thread on this project I had some fun with
https://forums.azbilliards.com/threads/my-amazing-full-spliced-player.463154/
Now when it comes to my opinion which is based on my personal experience as a player and a coach you should be good with a 62" cue. Believe me I've experimented enough with different set ups and I settled on a 62" cue because that is just enough for the most of the shots (on those few occasions where I need more to reach I can use butt extension), with the longer cue at the place I work I would hit the wall playing some shots off the short rail and of course the cuecase is another concern.
Here is me hitting with my 62" cue
https://m.youtube.com/channel/UCOFlN1ul1uFGCyvhnNlzaQQ/videos
If you have a 63" cue ... you like the hit and the only thing you want to experiment is the thickness of the grip area for your more comfortable grip... as it was already mentioned it is better experiment with something simple to get on to try, test, feel and see how it works and then decide if you need to build a new cue.
I remember when I first met the legend Mike Massey and saw some of his tricks when he had some fun picking and holding so many balls with one hand, or showing some of his fingerpool stuff... well I was just amazed ... he definitely has really big hands so as a stroke ... while playing not so extra thick or super long cue ... being quite a big man

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I wish you to find what feels and works the best for you.