Everyone here already gave you lots of good advice but I still would look into perhaps buying a set of used doubles when you're ready to buy as the savings can be significant. The classified here or craigslist can be a great resource. Even though double AL80s wont be terrible in fresh water, due to amount of neoprene you would be wearing or if you're going to be diving dry since you did say ice diving 
I would still prefer steel tanks over aluminum for the extra weight.
To give you an example, I purchased a set of double HP100s for 250USD and a set of double LP95s for 350. Both of those sets used are cheaper than buying a brand new set of Double AL80s.
Dont worry so much about the 300 bar versus 200 bar. Both are fine. You do not really gain anything by using a 300 bar manifold as the pressure rating doesn't make any difference.
I would still prefer steel tanks over aluminum for the extra weight.To give you an example, I purchased a set of double HP100s for 250USD and a set of double LP95s for 350. Both of those sets used are cheaper than buying a brand new set of Double AL80s.
Dont worry so much about the 300 bar versus 200 bar. Both are fine. You do not really gain anything by using a 300 bar manifold as the pressure rating doesn't make any difference.
