What to buy? Advise please!

[DSLR_Newbie]

I cannot comment on the L vs Non-L question but since I own a 100mm L IS Macro lens I think i can tell a bit about but beware its just my opinion and it might be different to your situation.

I am not a Professional photographer but a hobbyist and I own a 60D . I bought the 100mm IS L Macro when it was on special last year (799AUD).
but since its a specialized lens it stays most of the time in my bag and rarely comes out during spring or when i am stuck at home (not a lot).
I thought (that is just me) if I have a macro lens i will do more macro photography, but no, doesn't works like that.

If your case is like mine where you don't do a lot of macro shots all year around then Extension tubes or the non-L macro (60mm or 100mm) might be a economical choice but if you are into macro photography and do it a lot then by all means get the L Lens.

You need to determine what will be more useful 70-300 or the 100 Macro. You can use a 70-300 for macro using extension tubes but you cant use the 100mm macro to take 300mm shots.

hope this helps.