Several of their smaller models and some of their "quad" models are packed bed. Other quad models are not packed but are overfilled (resin comes up to where the dome starts) compared to the norm.
They do but very ineffective. If stuff gets in it doesn't like to come back out. Their packed bed units are intended for city water but still tend to be problematic.
A K50 had what they call a packed bed. Each tank requires .4 cu ft of resin. To achieve this you must fill the tank, tap tank on the floor, fill, tap ect until no more will fit. At the factory they actually use a vibrating pad under the tank.
Give supplyhouse.com a shot. Get registered as a business and get discounted prices. Most things are cheaper than anywhere else. Plus you can order at 2am in your tighty whities while drinking a beer and have it delivered for free.
You have to cut the pipe between fittings somewhere. Then replumb. I just stub the pipe, lay subfloor and flooring. Come back and cut the stub to the correct height with an inside pipe cutter and install new flange.