The paragon kiln you are looking at looks pretty good. I prefer firebricks. The extra inch of height is crucial.
Questions to additionally consider:
If your controller goes out, is it easily replaceable, repairable & can the kiln function without it? Those are important questions to ask.
I shopped for kilns starting two years before I finally purchased a kiln from Bruce at Satellite. The one I bought is about the same height & it is larger (holds 6 flasks efficiently) which for me was a huge plus. The controller I got is an Orton and stand alone unit. If the controller dies, the kiln can still be run manually with a reostat dial and temperature setting read.
I also got a shut down thermostat switch - a heat fuse of sorts (I can’t remember who makes it). If the controller or kiln exceeds my programmed highest temperature setting, it turns itself off. Its set +15 over my max. I do some cast in place gems and that’s a necessity. It also is a great safety feature. Before I built out my own studio, the studio I used didn’t have that feature, the programmer failed and kiln and controller were damaged. and all the the invested flasks were not to happy either. It was on an overnight burnout and disaster.
You will need to build some sort of efficient exhaust ventilation system over the kiln for burnouts if you are not steaming. I burn and don’t steam. Its quite stinky between 2-6 hours, more than you would ever think. I use a tall skinny flask as a mini chimney. My ventilation ducting hangs on an adjustable track overhead and never touches the kiln or flask. It overhangs the chimney flask so that no fumes escape. You can see a bit of wax residue inside the chimney on the top of the kiln sometimes.
I too have a basement studio of sorts and am extra careful (paranoid maybe) of fumes, good ventilation, fire hazards. I do have two large banks of windows, but that is not enough: mechanical ventilation is necessary.
There’s a large kiln shelf on the top of a vintage rolling tool stand (originally for a band saw I think) that the kiln is set up on. Its a great fireproof surface with a bit of extra edge for placing hot flasks as I move things around preparing to cast.
Personally, I prefer a centrifuge even though I have a vacuum caster, too.
And the electrical cord should be unplugged between uses. The cords get brittle and die for some reason (i heard that from my electrician, the kiln guy and a ceramic artist friend who it happened to.)
You are in the verge of an exciting adventure! Only time will tell if you use a 7" flask in your vacuum caster . . .