http://www.midwayusa.com/product/242364/remington-barrel-remington-870-12-gauge-3-18-1-2-fixed-improved-cylinder-bead-sight-parkerized
i have one of these on my 870. i had one of the mossberg made 870 barrels and this one is much nicer
it can be done if you have a drill press and a tap for it. but if the tap breaks or something happens while drilling the hole, it would be bad. contact utg first, and then maybe try to get the ones mossberg would use on the factory installed rail.
it sucks that they have to weld the stocks though. if i get one in that configuration, is it legal to make the folder operable again? and it looks like they are in stock at classic
i have a springfield 1911-A1 that i paid under $550 for. it's not US made, but it is pretty accurate and reliable. they also make a few different models for under a $1000.
if it is the same with both barrels, it is probably just the way you are looking at it. i had a mossberg made barrel on my 870 and it didn't fit as well as my 2 factory barrels.