First, get a 75+,
Second, get two XP3s
Regarding the E-bay sales, This was mentioned on this board a year or two after someone proposed a DIY canister filter. Started by bashing the OP, then told him/her to get a used canister filter. I don't trust filters I can't touch myself. Again, why I went DIY.
I dont see a Reason for two of them. a xp3 is rated for 100+ gallons...