When to use pxe and kpxe

[5chn4pp]

The buildtarget page mentions that there are many types of drivers like ipxe, intel, undionly etc. But I am a bit confused to which one I should choose. My requirements are that I need to support as many computers as possible, and speed is not a concern. So which one supports the most hardware? ipxe or undionly? pxe or kpxe?

Also i need to support 32bit Legacy, 32bit EFI, 64bit EFI and maybe 64bit Legacy. Am I correct in assuming the following options support the most hardware?

bin-i386-pcbios/undionly.kpxe
bin-i386-efi/snp.efi
bin-x86_64-efi/snp.efi
bin-x86_64-pcbios/undionly.kpxe

If not, please say which ones I should replace with what. Should I maybe replace .kpxe with .kkpxe for a wider support?

If it matters, the binaries are provided by ISC dhcpd when the clients do a PXE boot. After they are loaded they will provide a BzImage.