Well I ended up going with the IPV3. It really just came down to the price, which I got the IPV3 for only about $15 more than the IPV2s. Also since the IPV3 takes 2 18650s and if I just run it at about 20w it will last a loooong time xD
The ipv3 should be a performer for you. At 20 watts you will love the dual batts.