If you're using it for rock crawling...then you may want to stay electric..helps you keep your CG nice and low with the batteries, and the electric motors give you torque on depand instead of relying on engine rpm and clutch...
The Revo is supposed to ship in June....so based on backorders and delays I'd be surprised if you can get one in your hands before mid-july at the earliest.
The Savage is a great truck and quite durable, but the Monster GT also looks quite capable.
The Losi LST shows great promise and appears to even come with a REAL radio....3channel FM Synthesized radio...let's just hope it's the XS3 and not something that's been seriously watered down.
As much ad I'd want back in NOW...I'd probably wait for a little more info on the new offerings from Losi and Traxxas, and see how the Monster Gt does now that they're coming out of hibernation.
Remember..the MGT was released just in time for half the country to put them away for the winter...