Just because RPF have not done a 64bit version does not mean it is impossible
I use Gentoo64.
The Pi4B1 is cheaper than the 4B4 but 1GB is small for a dual screen OS.
Unless there is nice small OS
Any speed penalty between 32 and 64bit is now less important as the 4 is faster in everything.
With the dual screens that makes it a reasonable box for Desktop development.
But probably best to get the 4B4 when compiling things like the kernel.