The pricing on the table saw is perhaps a bit much. Is there a good reason to buy new? I've bought a few used Craftsman table saws for $5-$15 via auctions. A radial arm saw IMO is more useful overall, and would be for this project with the exception of ripping plywood or dimensional lumber lengths down to thinner dimensions. I've seen them used or at auction for $25-$50.
A final piece of equipment would be a miter saw setup. Not terribly expensive, but IMO absolutely necessary for nice trim work.
As for building the stand, since you haven't built one you've been happy with yet, if this is for a main display area in a formal location of the house (aka not the basement or a fishroom), $600 for something that looks great is probably well worth it.
If you have a suitable location, building a display into or through a wall might be easier to produce a beautiful display.
Personally, I've tried a couple nice cabinets before, both for a tank stand, and for other use, but building doors to look decent is seemingly impossible. If I tried it again, I'd purchase pre-made doors to use on the stand.