Not going to belittle the semantics of it. I had a Puma in my Landcruiser that had a small tank. It took the same amount of time to inflate a 33" tire, so I'm fine with this, tank or not.
$1250 for that compressor is a little spendy. I see some dealers selling it for under $1,000 and I'm sure that includes all the trim pieces and the hose. Still a bit pricey.
Lower cost options would be using an OEM right side storage compartment and installing it on the left side to store a stand alone compressor. Or using the kits available to mount an ARB compressor. ARB compressor is about $360 and the mounting box is another $120. I'm guessing all new Tacomas have the same wiring harness and there is a pigtail on the left side with the appropriate gauge wire and fuse.
Or just suck it up and buy the whole trailhunter.
I took last option and bought the Trailhunter! OEM compressor has some nice features. You can preset several inflation and deflation values so you don't have to monitor it. I haven't tried it yet, so we'll see...