Hands down, EVO has the best bolt on and weld on coil over kit - period.
The bolt on kit is only $3600 including coil overs, offers 12" of vertical travel up front, 11.25" of vertical travel in the rear and is totally reversible. The only real down side is that the rear coil overs are mounted low on the axle and exposed to rocks. Still, they are higher up than the competition and positioned more vertically than then too providing a better falling rate.
The EVO DTD with EVO Lever weld in kit is without question, the best coil over kit you can get bar none. No other kit out there offers a true 14" of vertical travel front and rear with bypass shocks and without cutting into the tube or leaving your coil overs hanging low on the axle. No other kit will allow you to do all this and still retain a low stance and no other kit out there can say that it's an Ultra4 race proven design. The biggest downside to the EVO DTD and EVO Lever is it's price tag. But, you do get what you pay for.