I doubt you will find very many with that combo. Gen 4s typically have 100k on them which mean tired springs and a very car like stance. 150 lb bumper would drag bit down even more. Not sure how that would look.
I havent got a front bumper yet .. But will end up putting one on with winch and stock springs within a year..i have 5100s already. Handling will be affected so you wilI have to relearn driving your truck regardless of spring setup. I would imagine if your not bombing around at any speed it should be ok for awhile.
I have had a couple other full size trucks that i have put big steel bumpers with 12k to 16k winches on with stock springs and they where fine. I did however run coil spacers on the front to level it out.
I think and I'm sure most others would agree. Smarter move would be to beef up the suspension before adding something like that. What is your purpose for the bumper? Just for looks? If just looks, I personally think it would look ridiculous with a bumper and no lift.
You can do just the front springs if you want to support the weight, but the shocks and probably pretty tired already, so may as well replace those at the same time.