Need some tips on screw selection for closet flange

I am replacing my bathroom's tile floor and will be screwing down a new closet flange. From what I've read online, the best screws to use for this are stainless steel. But I checked at Lowes and Home Depot, and they don't carry stainless steel screws big enough to screw down a closet flange. However, they did have some nice big #14 x 3" brass screws that fit perfectly into the flange screw holes. I am just wondering about their strength and rust resistance. Will the brass screws do just fine? Or should I shop more for stainless steel screws?

Also, does anyone have experience trying to drill screw holes in 3/8" thick porcelain tiles? I've been told to either cut out slots for the screws before installing the tile, or to buy a tile bit to drill the holes.

Thanks in advance for your tips. I Love this site (pardon the pun!).

Brass won't rust, but it isn't as strong as stainless steel. Go to a "real" hardware store, stainless steel screws may not be a big mover at HD and Lowes, but a complete hardware store will have them.

I already bought the brass screws -----

Since I already bought the brass screws, I'm wondering if they will be OK. How do the brass screws compare to stainless steel? Is the brass screw 90% as good as stainless steel? Are there people out there using brass screws regularly to attach a closet flange?

The brass screws should be fine. Some porcelain tile are nearly as hard as diamond, so many drill bits just won't touch it - that is why notching the tile prior to install is often worth the effort. The best thing to drill them is a diamond bit. I did get a carbide bit to drill through some porcelain, but the bit was shot by the time I finished, and it took about 10-minutes per hole - a real pain.