I see different numbers for table saw fence rails. Are they measured from the blade out or from the edge of the table out? And if it's left-tilt, does that figure in? I just have a one-car garage, so the saw would have to be mobile, which means a really long fence rail wouldn't work very well.
There are two things to consider. Overall length of the rails and the rip capacity.
Some saws are set up so you can saw on both sides of the fence/blade. Generally the rip capacity is list on the "wider" side. So a saw that states you can rip 30" will have that capacity on the dominate side. On the other side it may be half of that or less.
My saw has a 30" capacity. My previous fence would allow for 35". I fabricated the rails myself, and used that dimension on purpose because I thought I might want to cut ends for kitchen cabinets, and I did a few times. I upgraded to a Biesemeyer fence and it only has the 30" cut. Has not been a problem so far.
My blade tilts toward the fence when it is to the right of the blade. I like to make angled rips with the blade on the opposite side so the rip is not trapped under the blade and against the fence. If a piece is trapped it can and will kick back at astonishing speed, like and arrow. I am somewhat dyslexic and can not tell you which is a left tilt or right tilt. Which ever you buy make it a habit of work not to trap pieces under the blade.
I have a one car garage shop too and have the saw "aimed" at the garage door. any rip over 5 or 6", I open the door. Wheels help.
It might be worthwhile to ask first what kind of cutting capacity do you need, and then look for options to provide that capability. My tablesaw was purchased more than 20 years ago, before Festool and its track, so the only ways to accurate make large cuts on plywood sheets was either a tablesaw with a 52" rip capacity or a panel saw. I would suspect that rolling bases can be used on full size tablesaws with a 52" rip capability, but of course the long rails will take up more floor space even when the saw is not in use.
If you want the ability to rip long boards, some sort of outfeed support will be needed, another possible planning concern.
I have a 3hp cabinet saw. I bought it used and it came with two rail set. The first is 72 inches which allows for a 50 inch cut. Used to have it set up the way. Then as with you, I moved. Lucky enough to have a two car garage. The second rail set is 48 inches long and I now have set up for a 25 inch rip. I have it on a rolling stand with a 24 inch out feed table. As I have gotten older do not use big sheet goods often. When I do I have a track saw to break them down.
The table saw seems to get used as table as much as a saw but is there when I need it and nothing cuts like a cabinet saw. I would suggest you hang on to it. If the long rails are a problem then look for a shorter set. If after you try to work around it, it just does not work out then sell it and by the portable.