So im very keen on the 8051 and I kind of want to use it for programming. Like for righting code while Im away from the house. what compilers would be available to me? Sorry if these sound nubberish, the whole Other vs ARM vs Z80 vs 6503 vs x86 has thrown me for a loop.
No, it is not really suitable to use it for programming; you write your programs on a PC, and just use the 8051 to run those programs.
What kind of programs did you have in mind?
A large number of processor architectures can be used for solving a large number of very varying projects.
And a large number of processor architectures have free or at least cheap tools that can be used.
Maybe you should describe what you want to learn, or what kind of project you had in mind. Then we could help suggesting tools or processor or whatever.
Why have other alternatives send you in circles?