The Stig is on a mission in Alton at the moment helping needy street children that dont have there own CNC facilities but as I see it theres only one word
practice practice practice
the transition from Steel to Ally isnt tricky and steel is a lot cheaper in terms of consumables when you are learning.
Decent money will end up being spent for a unit that offers the flexibility to weld most allys, Cebora 1835 is groovey, nice toys to have would be
Post flow control
Square wave instead of sine wave
Balance control
Frequency control
HF start in place of scratch start (lift off isnt so bad)
a hat with a good quality filter helps a lot with ally
this bit might be tricky for Andy - cleanliness is next to godliness.
Blag Als - do a load of mileage until the hand/eye co-ordination is there (Nige might want to back of the Sherry a touch

) and then and only then start looking for a groovey rig. Oddly Mrs Jez picked a gun up and was flying in 30mins, some people take to it naturally, some have to work at it.
Remember it takes more current to weld ally than an equivilent thickness in steel
What was there excuse for canceling Nige?