You can't drop-in a barrel with a fully-supported, "ramped" chamber. The ramp replaces part of the frame that must be milled-out to accommodate the new barrel. The factory Delta Elite barrel has sufficient support for full-power ammo.
If you want to change springs in order to better accommodate hot rounds, I'd start with the mainspring, rather than the recoil spring. Heavy recoil springs do help slow unlocking and slide velocity somewhat, but they also can adversely affect feeding as the slide closes too fast. A heavy mainspring gives you the benefits of delaying unlocking and slowing the slide, without the downside of the heavy recoil spring. I run a 25# main and 20# recoil spring in my Delta, but most of my loads are 200@1000; for a steady diet of full power, I'd go back to the stock recoil spring rating of 23#.
I have a Cominolli recoil reducer in my Delta, which features polymer buffers on both sides of the guide rod head, so there is no metal-to-metal contact between the guide rod and frame. It might be overkill, but I got it for cheap.