Stripped screw replacement needed

[Kirk.AIA]

All I was trying to do is remove the 4 flathead hex screws holding the heatbed support arms to the belt carriage.
And of course, as is always the case, one hex screw stripped out.
Had to use a speedout extractor to get the screw out but now I need another flat head hex screw.

What size do I need to order as a replacement and where can I get one?

Edit: or should i splurge for the 4 point leveling upgrade? Its the same leveling support that I have and comes with the screws
I saw that in the description for the parts that come with the leveling support the screw size was noted.

Problem solved

[airscapes]

I have the 4point and had the same screws strip.. On mine the are 4 M3x16mm and 2 M3x10 flat head machine screws. You should be able to get at least the Philips version at the hardware store. I bought new bearings and rails from Makergear and they sent me the black hex drive screws