Hi Dennis,
I'm currently trying to make the same decision as you. I also briefly looked at the AL320G which appears to be a popular lathe, and the AL60 (a Seig C6) however I have very limited space in my workshop and a bench space of 1000x600mm max. so these two are, for me, too big.
H&F no longer sell the AL50, I had read somewhere that they and their customers weren't happy with the quality of the AL50 so have replaced it with the AL51 which is almost identical but apparently from another manufacturer (tho I now can't find where I read this. I think it was on the aussie woodwork forum *shrug*)
For me the Sieg C4, although rather more expensive than other machines of similar size, is winning out for quite a number of reasons.
However, there appears to be only two sources within Australia for the C4:
Carbatec has the C4, 410mm between centres. It was on sale (ends today) for $1668(incl. GST), normal price apparently $2005
http://www.carbatec.com.au/carba-tec-c4-metalworking-lathe_c19802
Ausee have a special version of the 'SC4' which is normally also 410mm BC, but theirs is 510mm BC. Priced at $1799
http://www.ausee.com.au/shop/category.aspx?catid=51
I wish H&F stocked the C4.
As far as I can tell, the C4 and SC4 are identical. Apparently the C4 was the first of the brushless lathes in the Sieg range. When Sieg started offering the older 'C' model lathes and 'X' model mills with new brushless motors as 'SC' and 'SX', they simply renamed the C4 to SC4 to fit in with their new naming convention.
The Ausee long bed version is appealing, but realistically, in almost a decade of owning a Sieg C3 I have never once wished I had more room between centres.
I had planned to visit Carbatec here in Perth yesterday to purchase a C4 on special, but they shut at 1pm and I got stuck doing more boring things. They are not open on Sundays, so seem's I have missed the special price
