Here comes the tricky part. Ohms. You have 2 options:

The Lecacy amp says its stable at 4-8 ohms. When you bridge it like that, youll be at 2 ohms, but unbridged youll be at 4 ohms. The subs will probably blow soon anyway, so if you dont plan on keeping the amp long at all anyway, then do whatever you want. But if you dont want the amp to blow up when you crank it, get a 4 channel amp thats 2 ohm stable like this http://cgi.ebay.com/ws/eBayISAPI.dll...090036424&rd=1

When you wire it a certain way (which ill describe in a sec) with a 1 channel amp, the result will be 4 ohms. And you will get a lil more power too. So id recommend getting a 1 channel amp and wiring it as follows, which will give u a 4 ohm load for the amp.
The + and - all the way at the left represents the amp output, the rest are where u hook up the speaker wire on the subs


I hope this helps and that i havent gone way over your head. Good luck