Actually, if you are looking at the HW-19 here on Audiogon, that Audioquest PT9 arm is the same arm as the Jelco, so you needn’t change out that arm. Excellent arm by the way!
However that table is a HW-19 JUNIOR so it doesn’t have the same top plate as the MKIII or MKIV. They use an acrylic/stainless steel sandwich which is MUCH heavier and denser than the MDF top plate of the Junior. Also the MKIII and MKIV have a removable arm-board where the Junior is a one piece plate.
The nice thing about the HW-19 is that is fully upgradable. You can change out the top plate, the armboard, the platter, the motor, the feet, the suspension, so it really easy to get a top notch table for a pretty decent price.
I was a VPI dealer for many years and have setup well over 100 of these tables and still currently have and use 3 different HW-19 tables. IMHO, still one of the best tables out there.