It's a good idea if you are running the stock front end stuff to switch to the tubular UCA's. Proper castor, weight, looks, strength and added clearance.
No argument here, I run tubular UCA's on all of my cars.
But they aren't mandatory either. If you're staying close to the factory ride height, or even just slightly lowered, and running 15" rims then you can run the stock UCA's with offset bushings and still have plenty of adjustment for a decent alignment.
If you're going significantly lowered (say 1" or more) with 17" or larger rims and wider tires I think the tubular UCA's just make good sense, same with 1" or larger torsion bars and good shocks. That will allow for a more aggressive alignment, which will work better with softer, modern compound tires. But it really depends on what you want out of the car, a lot of stuff I've done to my car is overkill if you just want a decent handling street cruiser.