the epx pro system with ezrun s-10 ESC and novatech 540 3300kv motor is honestly the one I would do. You will need to get a pinion gear 2 teeth higher, but other than that its a "drop in" deal.
And if you wanted to, you can get $50-$60 for the stock system on ebay or RCU marketplace (that system is $80 new on hobbypartz.com)
So, the epx pro system plus a pinion gear will cost you around $120 in total.
The Twister setup with lansu 90amp ESC and 3930kv motor (with 5mm shaft) will also need a pinion gear bought and run you pretty much the same.
Either system will provide more power as they have larger motors and can supply more amps to the motor.
The ezrun is the one I would get, as the optional program card is $10 on ebay and makes it easy to set the brake/punch control and other settings. Again, those settings will give you the power increase without ripping apart the truck.
One other small note, if you start using 3s lipo...plan on buying new tires before long. They will wear out fairly quickly, especially if driven on pavement. If you decide on getting one of the Redcat system, just PM me.