Hi. From my previous thread, I could get a 27-1/8 tire & a 1/4 tube. Thanks to all the people who replied to my thread. And I've encountered a couple of other issues...
Q1. It's a Panaracer tire. My previous tires would be at least several times thicker than this(I'm not sure the brand). The bike shop near my home said it's because the panaracer tire has a better quality, but I'm not convinced.
Q2. I didn't realize the tube is Schrader type. The previous one was Presta type, and the hole of the rim for air inlet is too small to use a Schrader type tube. It seems like many people enlarge the hole to fit a Schrader tube. But if I do that, will I still be able to use a Presta tube?

Yes, you can still use presta valved tubes. There are little collars to be had that will fill the space.

I use 27" tires, too, and although I have not used Panaracer, yet (the supply for my beloved IRC's seems to be drying up), I do appreciate the fact that they weigh from 100g to 200g less than some vintage 27" tires. The Panaracer Pasela is universally liked, here at B.F. Review any thread on them. I would not hesitate to use them. Do yourself a favor and get a presta 27"x 1 1/8" (700c x 28) tube. What type of surfaces do you ride on, what is your weight and do you plan on carrying heavy items (touring, grocery shopping, etc)?

Don’t file it out. Just buy presta tubes. Other than gas station air convenience, they are easier to work with in my opinion.

700x28 as mentioned above is the perfect tube. They seem to split the difference in terms of circumference and using them on 27” wheels usually is a snugger fit around the rim.

Panaracers are pretty good tires.
Don't drill your rim because of a tube purchase mistake. Just mark it up to experience.
Notice that 1989Pre recommended a smaller tube than the tire size, it makes installation easier.

I use 700 tubes with my 27" tires, I like the fit in the tire better when mounting them on the rim and Panaracers are a good quality tire. That's what goes on any bike I have with 27" wheels that I plan to keep. I also have a couple sets on 700c wheels.

And if that’s a problem just get an adapter - they’re cheap and small.

Panaracer tires work well for me on both 27” and 700c rims. I use Presta valves on all my bikes , the same tube size fits both sizes.

I have always have a Schrader-to-Presta adapter screwed onto one of the small protruding bolt ends on every bicycle I have owned. The mountain bike has one on the end of one of the thumb shifter mounting screws.