powering 2 15 L7's???

hehe don't think you'll need to worry about exceeding the RMS level of those subs.  There are so many different amps out there and many will push your subs just fine; however, I think that you'd get the most bang for your buck from a JBL Power Series BP1200.1.  They can be found on ebay for under 300 although just be aware of who you're purchasing from and what kind of return/warranty policies they have.

ANYWAYS, about the amp...it is 1 ohm stable, though it puts out the same amount of total power at 2 ohms as it does at 1 ohm.  The 1 ohm stability just means you have more flexibility with the wiring of subs.  It puts out 1200 watts RMS at 2 ohms, so you'd be sending 600 watts RMS to each sub.  It does require a 150 amp ANL fuse and at least 4 gauge power cable, and in most vehicles a high output alternator is highly recommended if you plan to be pushing this amp to it's limits.  Capacitors may temporarily solve problems with lights dimming but in the long run I'd go for a HO alternator.  Of course this depends on what kind of vehicle you have....

Yes there are other amps that will put out power closer to the 1000 watt max RMS rating of the L7s ( Audiobahn A18001DQ for example) but you probably could get two of  the JBL amps for less than the cost of a single 2000 watt amp.  Just my 2 cents though.

oh and I forgot to ask, are you going for SQ or SPL?  Or somewhere in between?