Yes they are good tanks, the myth regulator is shorter than most and allows you to play a bit tighter. But before you get anything you should invest in a good mask, it is the single most important piece of equipment you can get. I can give you some suggestions if you can tell me what your budget is.
I had the option between the G4 and the mini, and I chose the g4. I love the feel of the G4, and it looks great too. The only problem with it is bolt stick, you can fix it easily by cleaning the DP 40 lube off the bolt and and putting some good quality lube on it like Dow 33. It is also one of the lightest markers in the world, lighter than the mini in fact. And the RAPS flip lever asa is one of, if not the best on/off asa in the industry. Another thing I'd like to say is that I don't understand why the blitz is even one of your options, I mean it's a good beginner gun but it' can't even compete with these other markers . I would like to clarify that this is my opinion and that the invert mini is an amazing marker, I can't give enough props to the mini. I would Suggest that you go to your local pro shop and and ask to hold the markers and see which one feels better. Let me know what you decide on bro !