Hi Vagelis,

Just be aware the running costs of TIG are far more expensive compared to MIG. It's not just the buying of the TIG there are hidden costs.

Gas needed for aluminium is Pure Argon or Helium argon Mix for more specialist aluminium welding which costs lot more than typical 5% mix Mig gas and lot more expensive than Co2.
Tig is much more dependant on Gas flow so you need Gas Flow meter not just Regulator showing pressure like most Mig setups use.
Also because off the Slow nature of Tig welding compared to Mig the Gas usage is higher. Mig will cover lot more Mtr's of weld for the same gas usage. And it's cheaper Gas.

Then you have the Torch setup. For best control and weld flow you really need a foot pedal so have full control of amps. Tig torches with switch are ok for awkward places but are limited for fine work because they don't have the same control you have with foot pedal.
Also standard Tig cups are Ok but for better welds you'll soon want to use Gas lense so that's more hidden expense. They do however pay for them selfs long term because you tend to use less gas or should say waste less gas.

So what I'm saying is really look if you need TIG because it's not cheap. Also welding Aluminium with TIG takes a good while to learn and is very unforgiving. Can be very frustrating for first time user because just touch down the Tungston one time and you have to stop and clean/regrind the Tip.
Also If you Eye sight is at all dodgy TIG will soon find out because TIG is much more visual. Good Auto shield helmet designed for TIG is a Must because TIG fires much quicker than Mig and is Lot brighter so the helmet needs to respond faster to the Arc.

My Tig is 200A form R-tech and I love it. But it took me nearly half of Large Bottle of Gas before I got anything like resonable at welding Aluminium and I ground a lot of tungston.!!! . . . I relate TIG to Old Fashioned Gas welding and I was very very good at it in my youth having welded more Cars than Ford so thought TIG would be easy.!! I was Wrong and it was real Eye opener. Thou must Say I do love TIG now but only For Aluminium and Titanium or Stainless for most things in Steel I'll always turn to MIG because it's so much faster.