I have a 05' gmc 4wd 1500, are there any nice lifts out there that get rid of the torsion bars and use coilovers instead?, are there any lifts that clear 37s?  

You have picked the wrong truck for this. Even if you find a coil over kit for it the front end is not strong and you will have alignment issues and short ball joint life and shorter steering component life too. Plus, you will not have enough brakes to be effective with these tires and front and rear drive axles will be loaded beyond design limits and will fail unless you baby it. Then there is axle ratios which will need to be changed or you will have snail like performance and short tranny life too. Sorry to be a downer here but if you want to try this you should at least start with a 3/4 ton which has a stronger frame, better ball joints, better tranny, bigger drive axles and bigger brakes too. I might mention too that any warranty that you might have on drive train will go right out the window too with this mod.  

as long as you dont go over 35 inc tires and regear,        your axles and tranny should be fine.  Finding a coilover conversion kit is useless as i doubt they exist, you need to take your truck to a prerunner shop and have them fab up a custom coil over suspension with the requeried stonger duty steering/tie rod and alignment stuff, yes it will be expensive when compared to a bolt on ifs lift but you will have way better performance than any torsion bar lift kit and a much smoother ride than stock if you have your shocks properly valved along with progressive leaf springs and equally valved shocks in the rear axle.