Ahh so they are slightly differant.
The astra has 88b Harrison on the bottom, it is quite a bit larger (190wx180t) as oppose to your 185x160 and yes they have the 45deg outletts as std.
Yes they are copper fins covered in solder but use brass tanks.
The novas look good aswell. Probably quite a bit easyer to fit in the case. Im having trouble trying to fit 2x astra cores in a cheiftech dragon midi